0.10.x: Add in contents of Pull-Request-Validation wiki page, with check boxes, into PR template itself

[stephengtuggy]

Thank you for submitting a pull request and becoming a contributor to the Vega Strike Core Engine.

Please answer the following:

Code Changes:

• This is a documentation change only

Issues Addressed:

• Implements Add contents of the play test plan to the Pull Request template #1689 for 0.10.x

Known Issues Remaining:

• Nothing new that I'm aware of, except that it should be noted that several of the screens off the Main Menu have been displaying the wrong version number and the wrong (SourceForge) URL for some time now

Purpose:

• What is this pull request trying to do? Implement Add contents of the play test plan to the Pull Request template #1689 for 0.10.x, adding the actual contents of the Pull Request Validation wiki page into the PR template itself, with check boxes next to each item.
• What release is this for? 0.10.x
• Is there a project or milestone we should apply this to? 0.10.x