* Add the pull-request template
* Rewording
* Replaced checklist link, added Rat exclusion
* Update the PR template. Add Concurrency Checklist to the repository
* Merge Description and Design sections. Softer language. Removed requirement to test in production environment. Added a committer's instruction to justify addition of meta tags.
* Rephrase item about comments
* Add license header
* Add item to concurrency checklist
Roman Leventov