chore(ci): Automate Releases

[cschiewek]

This PR aims to automate the process of publishing releases to hex.pm.

Currently we need to manually update the changelog, create and push the tag, publish the release in github, and publish to hex. This makes publishing package updates onerous.

This automates all of that by:

• Enforcing conventional commit messages for PR titles to enable automatic changelog updates
• Leveraging the release-please to create and update release PRs, which track changes to the changelog and version bumps, and create releases when release PRs are merged.
• Add a github action to publish the package to hex.pm when a github release is created.

Before merging this, there are a few things that need to happen in github:

• Create an org level secret named ORG_GITHUB_TOKEN that contains a github token with permissions to write contents and pull requests.
• Create an org level secret named HEX_API_KEY with permissions to publish to hex.
• Update merge settings to:
  • Only allow squash & merge
  • Default PR titles to commit message

I do not have permissions to do those things, so if everyone on @absinthe-graphql/creators could do that for me, or give me permissions to do so, that'd be 💯 .

[cschiewek]

@benwilson512 I would really love to move this forward. Could you please give me appropriate permissions to do the following (or alternatively do these things):

• Create an org level secret named ORG_GITHUB_TOKEN that contains a github token with permissions to write contents and pull requests.
• Create an org level secret named HEX_API_KEY with permissions to publish to hex.
• Update merge settings to:
  • Only allow squash & merge
  • Default PR titles to commit message

Thank you.