Fixed Contributor Guide Issues

[priyaananthasankar]

Fixed following issues:
#68 #69 #70 #71 #80

Provided Python debugging instructions through VS Code
Extended debugging instructions for DurableTask
Used ExtensionBundles in host.json and provided links for any reference
In the end, do review the Release process.

Removed investigations internal folder
Removed API_IMPLEMENTATION_STATUS: It is captured in CHANGELOG. The non implemented ones will have an issue raised in Github.

[davidmrdavid]

This is great! Thank you for this work.
I like that the guide has been simplified greatly and it works under the assumption that the contributor is familiar with the framework, which is precisely right!

Two final requests:

1. The samples work with Python 3.7.x and 3.6.x but not w/ >=3.8.x . Please update the requirements listing to show this :)
2. Please add @davidmrdavid as well for requesting pypi releases

That's all for me, then I'll accept and we'll merge!

[priyaananthasankar]

2. Please add @davidmrdavid as well for requesting pypi releases

@davidmrdavid : Sure thing. Also I found another real good approach for automated CD PyPI releases. Its a good practice to use github.com Releases and release a specific version say vXX.XXX.XXX and kick off the CD pipeline release into PyPi when it senses a GitHub release. Haven't tried it but its good learning :)

[davidmrdavid]

Oh cool! Let's do it that way moving forward, I think it would be good for our users, and us, when resolving issues.

[priyaananthasankar]

@davidmrdavid : So if any sample requires a specific Python version, I would want to mention that in that sample's README doc. As for this library itself, there is nothing pinning it down to specific Python versions as yet. So I believe we can leave the pre-reqs section as-is and I put a note in the pre-reqs section for folks to check version compatibility of any specific ML lib people want to use.

[davidmrdavid]

Looks good to me!