* Move changelog out of README into a separate file
* Expose the changelog to Sphinx
* Integrate Towncrier configuration into the repo
* Include the change fragment docs in Sphinx
* Add a config for the Chronographer GitHub App
* Add a change note for PR #823
* Update CHANGELOG.md
Co-authored-by: Abhinav Singh <126065+abhinavsingh@users.noreply.github.com>