Don't require a new release for readme updates

[soup-bowl]

Note to self to add a new deployment process to check exclusively for readme changes of the project root, so that for readme updates and changes to the tested status don't require a new version tag to be launched, or manual intervention with the Subversion repository.

Related: https://github.com/10up/action-wordpress-plugin-asset-update

[soup-bowl]

Removed from milestone - Experiencing other difficulties with the Action deployment, don't want to risk it extending.

[soup-bowl]

This project follows a bastardised version of the Git Flow. A consideration could be to adjust the CI/CD process so that:

• Create develop branch and lock main (not strictly necessary).
• Tags are still deployed via releases main, but the main plugin readme is not updated.
• Readme is sourced from changes to the readme main branch.