### What?
This commit makes sure `create-next-app` doesn't ignore user's git configuration (`init.defaultBranch`).
### Why?
Hard coding configurations of a user is annoying (for the user).
Co-authored-by: Steven <229881+styfle@users.noreply.github.com>
* Initialize Git repo on app creation
This PR initializes a Git repository after Create Next App runs.
We ensure the app was not created in an already-existing Git or Mercurial repo.
Failures of setup (no Git installed) do not fail the application bootstrapping.
Closes#9077 (replaces)
* Add test
* Update index.test.js