Add link to the github location of the notebook

[nhirschey]

The readme.md links that automatically open visual studio is a great experience if you have the notebook extension installed. However, if you don't have the notebook extension installed when you first come to the site (👋 ), then nothing happens when you click on the link and it seems like something is broken. I eventually saw the "Links below require Visual Studio 2022 and Notebook Editor Extension" but it was not immediate.

Would it make sense to also add a link to the github URL of the notebook?

Something along these lines below might be more obvious. I don't know what to call things, the main point is two links:

#	Topic	Notebook link (requires VS and notebook extension)	Github link
1	Intro to Machine Learning	01 Notebook	01 Notebook

Or..

#	Topic	Notebook link
1	Intro to Machine Learning	01 Notebook / Github version

[beccamc]

Thanks for reporting! I've updated the readme with your suggestions.

I'll keep this open for @JakeRadMSFT to also make some edits to the "Next notebook" link at the bottom of the series.