Fix a few typos (#210)

Author: amartini51

TSPL.docc/LanguageGuide/Macros.md

@@ -568,7 +568,7 @@ is a freestanding macro that produces an expression,
 so the `FourCharacterCode` type that implements it
 conforms to the `ExpressionMacro` protocol.
 The `ExpressionMacro` protocol has one requirement,
-a `expansion(of:in:)` method that expands the AST.
+an `expansion(of:in:)` method that expands the AST.
 For the list of macro roles and their corresponding SwiftSyntax protocols,
 see <doc:Attributes#attached> and <doc:Attributes#freestanding>
 in <doc:Attributes>.

TSPL.docc/LanguageGuide/Properties.md

@@ -488,7 +488,7 @@ struct AlternativeRect {
 
 If the entire body of a getter is a single expression,
 the getter implicitly returns that expression.
-Here's an another version of the `Rect` structure
+Here's another version of the `Rect` structure
 that takes advantage of this shorthand notation
 and the shorthand notation for setters:
 

TSPL.docc/ReferenceManual/Attributes.md

@@ -2295,7 +2295,7 @@ You can apply that attribute in the following places:
 Applying a result builder attribute doesn't impact ABI compatibility.
 Applying a result builder attribute to a parameter
 makes that attribute part of the function's interface,
-which can effect source compatibility.
+which can affect source compatibility.
 
 ### requires_stored_property_inits
 

TSPL.docc/ReferenceManual/Declarations.md

@@ -1471,7 +1471,7 @@ Calls to a throwing function or method must be wrapped in a `try` or `try!` expr
 The `throws` keyword is part of a function's type,
 and nonthrowing functions are subtypes of throwing functions.
 As a result, you can use a nonthrowing function
-in a context where as a throwing one is expected.
+in a context where a throwing one is expected.
 
 You can't overload a function based only on whether the function can throw an error.
 That said,
@@ -3182,7 +3182,7 @@ even if the extensions' requirements are mutually exclusive.
 This restriction is demonstrated in the example below.
 Two extension declarations attempt to add conditional conformance
 to the `Serializable` protocol,
-one for for arrays with `Int` elements,
+one for arrays with `Int` elements,
 and one for arrays with `String` elements.
 
 ```swift

TSPL.docc/ReferenceManual/Expressions.md

@@ -1364,7 +1364,7 @@ the type of `x` matches the type implied by its context exactly,
 the type of `y` is convertible from `SomeClass` to `SomeClass?`,
 and the type of `z` is convertible from `SomeSubclass` to `SomeClass`.
 
-> Grammar of a implicit member expression:
+> Grammar of an implicit member expression:
 >
 > *implicit-member-expression* → **`.`** *identifier* \
 > *implicit-member-expression* → **`.`** *identifier* **`.`** *postfix-expression*

TSPL.docc/ReferenceManual/SummaryOfTheGrammar.md

@@ -439,7 +439,7 @@ make the same change here also.
 > *capture-list-item* → *capture-specifier*_?_ *self-expression* \
 > *capture-specifier* → **`weak`** | **`unowned`** | **`unowned(safe)`** | **`unowned(unsafe)`**
 
-> Grammar of a implicit member expression:
+> Grammar of an implicit member expression:
 >
 > *implicit-member-expression* → **`.`** *identifier* \
 > *implicit-member-expression* → **`.`** *identifier* **`.`** *postfix-expression*