Summary:
This moves the Template files to the .github folder. This helps clear up the extra files in the root of the directory.

This is my first PR 😄  and I plan to contribute more to this awesome project.
Closes https://github.com/facebook/react-native/pull/7854

Differential Revision: D3424679

fbshipit-source-id: 2baca0bb4182eb6d803836e10a5434d980e7d0c3