Customise GitHub issue templates

[RussKie]

https://docs.github.com/en/github/building-a-strong-community/configuring-issue-templates-for-your-repository#configuring-the-template-chooser

[gerhardol]

VS Code x2, IntelliJ from README
Add Git? https://github.com/git-for-windows/git/issues/new

Great

[RussKie]

VS Code x2, IntelliJ from README
Add Git? git-for-windows/git/issues/new

I did consider those, but we don't want to make too long.
In the last 4 years or so I've seen only a handful of actual git issues mistakenly raised here. For other extensions we haven't received any issue at all, so I don't think it is worth adding them, making the list unnecessary long.

[RussKie]

@msftbot merge in 48 hours

[ghost]

Hello @RussKie!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

• I won't merge this pull request until after the UTC date Fri, 10 Jul 2020 12:48:39 GMT, which is in 2 days

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".