Add Changesets

[estrattonbailey]

This PR adds Changesets into the mix. Changesets handles versioning, publishing, the creation of CHANGELOG.md documents, git tags and GitHub releases.

The basic process is this:

1. You edit some files
2. If these file edits should result in a version change to the package, add a changeset along with the other files in the commit
   1. You can add as many changesets (for as many packages as needed) to a PR as you want, they will be flattened
3. Commit your edits and changeset(s)
4. Push up your PR

This PR contains an example changeset atm.

From this point:

5. You would merge your PR
6. Changesets gathers all *.md files from .changeset dir, and creates and maintains a separate PR with the version bumps required
7. Other PRs with other changesets may be merged in the meantime
8. When ready to publish, we merge the Changesets maintained PR
9. Changesets publishes all updated files to npm
10. Changesets updates changelog files and tags
11. Changesets commits changelogs, tags, and a release back to the repo

TODO

• don't build images on merge to main
• add NPM_TOKEN to this repo's secrets
• confirm there's nothing we need to do to ensure changesets starts at our current versions (we have no git tag history or releases rn)
• format changelogs after versioning (optional)
• update-main-to-dist

[estrattonbailey]

If merged, this should result in a patch for api, an update of the api package in each package that relies on it, and a patch of their versions as well.

In the CHANGELOG.md, this comment will appear along with the git hash so that changes can be easily linked to the actual edited files.

[estrattonbailey]

Removed this, but you get the idea

[dholms]

this all LGTM 👍

excited to see it in action

[estrattonbailey]

This will run on merge into main, but will only publish if ./.changeset/*.md are present.

[estrattonbailey]

We can change these values to whatever we want