* docs: update PR template and README with feature PR restrictions
Add temporary hold notice for Redux/IndexedDB feature PRs in both pull request template and README
Fix whitespace and formatting inconsistencies in README
* docs: update contributing guidelines with temporary PR restrictions
Add important notice about temporary restrictions on data-changing feature PRs
Clarify acceptable contribution types during v2.0.0 development phase
* docs: remove warning about feature PR restrictions
The warning about temporary restrictions on feature PRs involving Redux or IndexedDB changes has been removed as it is no longer relevant
* docs: remove core developer membership section from contributing guides
