.github: reinstate ISSUE_TEMPLATE.md for microsoft/git

We had been using the default issue template from git-for-windows/git,
but we should ask different questions than Git for Windows. Update the
issue template to ask these helpful questions.

Signed-off-by: Derrick Stolee <[email protected]>

Author: derrickstolee

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,68 @@
+ - [ ] I was not able to find an [open](https://github.com/microsoft/git/issues?q=is%3Aopen)
+        or [closed](https://github.com/microsoft/git/issues?q=is%3Aclosed) issue matching
+        what I'm seeing, including in [the `git-for-windows/git` tracker](https://github.com/git-for-windows/git/issues).
+
+### Setup
+
+ - Which version of `microsoft/git` are you using? Is it 32-bit or 64-bit?
+
+```
+$ git --version --build-options
+
+** insert your machine's response here **
+```
+
+Are you using Scalar or VFS for Git?
+
+** insert your answer here **
+
+If VFS for Git, then what version?
+
+```
+$ gvfs version
+
+** insert your machine's response here **
+```
+
+ - Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?
+
+```
+$ cmd.exe /c ver
+
+** insert your machine's response here **
+```
+
+ - Any other interesting things about your environment that might be related
+   to the issue you're seeing?
+
+** insert your response here **
+
+### Details
+
+ - Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other
+
+** insert your response here **
+
+ - What commands did you run to trigger this issue? If you can provide a
+   [Minimal, Complete, and Verifiable example](http://stackoverflow.com/help/mcve)
+   this will help us understand the issue.
+
+```
+** insert your commands here **
+```
+ - What did you expect to occur after running these commands?
+
+** insert here **
+
+ - What actually happened instead?
+
+** insert here **
+
+ - If the problem was occurring with a specific repository, can you specify
+   the repository?
+
+   * [ ] Public repo: **insert URL here**
+   * [ ] Windows monorepo
+   * [ ] Office monorepo
+   * [ ] Other Microsoft-internal repo: **insert name here**
+   * [ ] Other internal repo.