Configuring codespaces (#19219)

* updating configuring doc

* Adding some content changes

* pre-built -> predefined to match vscode

* reorganizing

* moving guides around, rewriting about

* adding reference folder

* fixing brooken links

* clarifying and simplifying about doc

* removing limitations

* Apply suggestions from code review

Co-authored-by: Allison Weins <[email protected]>
Co-authored-by: Sarita Iyer <[email protected]>

* review changes

* Update content/codespaces/setting-up-your-codespace/configuring-codespaces-for-your-project.md

Co-authored-by: Allison Weins <[email protected]>

Co-authored-by: Allison Weins <[email protected]>
Co-authored-by: Sarita Iyer <[email protected]>

Author: 3 people

content/codespaces/about-codespaces.md

@@ -26,26 +26,26 @@ topics:
 
 A codespace includes everything developers need to develop for a specific repository, including the {% data variables.product.prodname_vscode %} editing experience and common languages, tools, and utilities. {% data variables.product.prodname_codespaces %} is completely configurable, allowing you to create a customized development environment for your project, and allowing developers to personalize their experience with extensions and dotfile settings. 
 
-Codespaces offers many benefits to all teams by allowing for a consistent environment across your entire team, fast onboarding, and creating a secure space for development.
+Codespaces offers many benefits to teams by allowing for a consistent environment across your entire team, fast onboarding, and creating a secure space for development.
 
 
 ### A consistent environment
 
-You can create a single codespace configuration that defines the environment of every new codespace that anyone creates for your repository. Once you've made a configuration, developers don’t have to worry about installing the right tools to comment, review, or contribute. The standard environment is already available for them as soon as they create a codespace from the repository. For more information, see "[Configuring {% data variables.product.prodname_codespaces %} for your project](/github/developing-online-with-codespaces/configuring-codespaces-for-your-project)."
+You can create a single codespace configuration that defines the environment (or _dev container_) of every new codespace that anyone creates for your repository. Once you've made a configuration, developers don’t have to worry about installing the right tools to comment, review, or contribute. A standardized environment is already available for them as soon as they create a codespace from the repository. For more information, see "[Configuring {% data variables.product.prodname_codespaces %} for your project](/github/developing-online-with-codespaces/configuring-codespaces-for-your-project)."
 
 For help getting started with configurations for specific languages, see the [Getting Started](/codespaces/getting-started-with-codespaces) tutorials.
 
 While every codespace created from your repository has a consistent development environment, developers can use {% data variables.product.prodname_codespaces %} wherever they need it – on {% data variables.product.prodname_dotcom %} or through {% data variables.product.prodname_vscode %}.
 
 ### Fast and personal onboarding
 
-With a [dev container](/codespaces/setting-up-your-codespace/configuring-codespaces-for-your-project#about-dev-containers) already configured in your repository, any new developer can quickly onboard with the correct development environment for your project by using the {% octicon "download" aria-label="The download icon" %} **Code** drop-down menu, and selecting **Open with Codespaces**.
+With a [dev container](/codespaces/setting-up-your-codespace/configuring-codespaces-for-your-project#about-dev-containers) configured in your repository, any new developer can quickly onboard with the correct development environment for your project by using the {% octicon "download" aria-label="The download icon" %} **Code** drop-down menu, and selecting **Open with Codespaces**.
 
 ![Open with Codespaces button](/assets/images/help/codespaces/open-with-codespaces-button.png)
 
-Developers can start coding faster by reducing time spent configuring their environment.
+As a result of standardizing on a repeatable developer environment, developers can get started with a new codespace without doing any manual configuration and do not need to do continued maintenance of their developer environment. A new codespace can be created when starting a new feature.
 
-Developers can also personalize aspects of their codespace environment by using a [dotfiles](https://dotfiles.github.io/tutorials/) repository. Personalization can include shell preferences, additional tools, editor settings, and extensions, such as Live Share. Personal customizations are stored on a per-user basis, so every codespace a developer opens has their environment ready to go. For more information, see "[Personalizing {% data variables.product.prodname_codespaces %} for your account](/github/developing-online-with-codespaces/personalizing-codespaces-for-your-account)."
+Developers can also personalize aspects of their codespace environment by using a [dotfiles](https://dotfiles.github.io/tutorials/) repository and [Settings Sync](https://code.visualstudio.com/docs/editor/settings-sync). Personalization can include shell preferences, additional tools, editor settings, and extensions, such as Live Share. Personal customizations are stored on a per-user basis, so every codespace a developer opens has their environment ready to go. For more information, see "[Personalizing {% data variables.product.prodname_codespaces %} for your account](/github/developing-online-with-codespaces/personalizing-codespaces-for-your-account)."
 
 Because {% data variables.product.prodname_codespaces %} can be accessed in the browser, developers can work on multiple projects by switching between tabs.
 

content/codespaces/setting-up-your-codespace/configuring-codespaces-for-your-project.md

@@ -24,7 +24,7 @@ A development container, or dev container, is the environment that {% data varia
 
 {% data reusables.codespaces.devcontainer-location %}
 
-You can use your `devcontainer.json` to set default settings for the entire codespace environment, including the editor, but you can also set editor-specific settings for individual Workspaces in a codespace in a file named `.vscode/settings.json`.
+You can use your `devcontainer.json` to set default settings for the entire codespace environment, including the editor, but you can also set editor-specific settings for individual [workspaces](https://code.visualstudio.com/docs/editor/workspaces) in a codespace in a file named `.vscode/settings.json`.
 
 For information about the settings and properties that you can set in a `devcontainer.json`, see [devcontainer.json reference](https://aka.ms/vscode-remote/devcontainer.json) in the {% data variables.product.prodname_vscode %} documentation.
 
@@ -73,7 +73,7 @@ Predefined container definitions include a common configuration for a particular
 
 Using a predefined configuration is a great idea if you need some additional extensibility. You can also start with a predefined configuration and amend it as needed for your project's setup. 
 
-1. To access the command palette, in the bottom-left corner click **Codespaces**, then start typing "Codespaces: Add Development Container Configuration Files...". Click **Codespaces: Add Development Container Configuration Files...**
+1. To access the command palette, in the upper-left corner, select the Application Menu and click **Command Palette…** from the **View** menu, then start typing "Codespaces: Add Development Container Configuration Files...". Click **Codespaces: Add Development Container Configuration Files...**
   !["Codespaces: Add Development Container Configuration Files..." in the command palette](/assets/images/help/codespaces/add-prebuilt-container-command.png)
 1. Click the definition you want to use.
   ![List of predefined container definitions](/assets/images/help/codespaces/predefined-container-definitions-list.png)
@@ -88,7 +88,7 @@ Using a predefined configuration is a great idea if you need some additional ext
 
 If none of the predefined configurations meet your needs, you can create a custom configuration by adding a `devcontainer.json` file. {% data reusables.codespaces.devcontainer-location %}
 
-In the file, you can use supported configuration keys to specify aspects of the codespace's environment, like which {% data variables.product.prodname_vscode %} extensions will be installed.
+In the file, you can use [supported configuration keys](https://code.visualstudio.com/docs/remote/devcontainerjson-reference) to specify aspects of the codespace's environment, like which {% data variables.product.prodname_vscode %} extensions will be installed.
 
 {% data reusables.codespaces.vscode-settings-order %}