- updated release pull request description template to be more condensed and require no editing.
- moved some elements of release pull request items into pull request template (handled at the PR level instead of the release level).
- updated the release pull request checklist templates to include mobile and desktop test coverage for ui changes.
* add doc for feature flag and experimental interfaces
* add new doc to TOC
* update pull request template to include checklist item for experimental/feature flag items
* tweak wording for experimental prefix
* fix bad formatting of bold for lines
* fix double slash in url
* add missing sentence case
* remove account signup as that is not included in Cart and Checkout block logic.
* Fix typo