Simplify Git in Visual Studio page

[prnadago]

• [x] I provide my work under the project license.
• [x] I grant such license of my work as is required for the purposes of future print editions to Ben Straub and Scott Chacon.

Changes

The current page has outdated content about Team Explorer. The default Git tooling in Visual Studio has been updated. It's probably best to simplify this page to briefly highlight the Git functionality and point readers to the official docs where they can read a lot more about the details.

I've also removed the screenshots since the team is going to continue enhancing the Git tooling in VS for at least the next year. The screenshots are going to get outdated pretty fast. The link to the Visual Studio documentation will stay up to date with the latest screenshots and functionality.

Context

Fixes #1451

[prnadago]

@HonkingGoose thanks for approving. Anything else I need to do to get this merged?

[HonkingGoose]

This needs a review/merge from somebody with write level rights. I only have read rights so I can't merge this PR. 😉

I'll ping @ben (maintainer of this repository) for a review.

[ben]

Fabulous, thanks!