Because we use the release-please bot, commit messages to main must follow the Conventional Commits specification. This is soon to be (but not yet) enforced by the commitlint tool. This requirement is only enforced on the main branch. Commit messages in PRs can be whatever you want them to be. "Squash" mode must be used when merging a PR, with a commit message that follows the Conventional Commits specification.
This repo uses the release-please bot. Release-please will automatically open a PR to update the version of the repo when a commit is merged to main that follows the Conventional Commits specification. The bot will automatically keep the PR up to date until a human merges it. When that happens the bot will automatically create a new release.