Update issue template so that removing the carriage return doesn't merge the user's text with the list/bullet item.

Documentations for Github users. Metrics: Fixed display of NavRectRel, added display of ParentWindow.

Documentation bits. Misc comments.

Contribution guidelines

Contributing: tweaks, mention screenshots more prominently.

Updated templates, added pull request template.

Update issue_template.md

Update issue_template.md

Update issue_template.md

Update issue_template.md

Create issue_template.md

Contributing guidelines for issues

Create issue_template.md