Add documentation around the craft publish process

[AbhiPrasad]

1. Setting up https://github.com/getsentry/craft (mostly just a summary of the README) a. What changelog policy to use b. What targets to set c. Setting up a version bumping script, and some examples
2. Using the publish workflow https://github.com/getsentry/publish a. When to request a release and how to fill out the action form b. How does release process differ for alphas/betas c. Who can approve the release https://github.com/orgs/getsentry/teams/release-approvers d. Troubleshooting a failed release