chore: resetting main to v1.0 - remove main protection

[klesh]

Summary

Currently, the default main branch points to the development branch which confuses new contributors when they try to fix some minor issues during setup. After some discussion, we decided to switch it to the stable branch to make things easier for everybody.

Plan

1. Remove protection from main branch
2. Reset it to release-v1.0 branch
3. Publish a new branch named next (for development)

Impact

1. Bugfixes go to the main branch, then optionally create another PR to the next branch.
2. New features go to the next branch
3. Maintainer would cherry-pick necessary bugfixes to the next branch before releasing.