Update `prer` to use commit messages and or PR content so release notes can be generated

[mikeldking]

Description of the problem / feature request:

Previously we were able to construct release notes by hovering over the commit hashes but GitHub has removed showing previews of the PRs linked to the commits.

The commit history on the PR branch can no longer be used to crate release notes easily

Feature requests: what underlying problem are you trying to solve with this feature?

prer should automate or make it easy to view all the commit messages that resulted in the manifest changes. E.g. automate the release notes.

Have you found anything relevant by searching the web?

Automating release notes via commit messages: https://www.conventionalcommits.org/en/v1.0.0/

[apesternikov]

Would it be sufficient to create a list of PR numbers like this?

• fix dep list query string construction #112
• add missing name suffix configuration #111
• Update workspace_snippet.sh #110
  or list of shas
• 1623bb7
• 1cbc2e9
• 1cbc2e9

[mikeldking]

@apesternikov List of prs seems the cleanest? I think either will work for our use cases. As long as it gets close to human parsable release notes via commit messages we will be happy

[apesternikov]

fasterci (fasterci) free tier has a support for automatic updating rules_gitops PRs description for github. proper support in prer should include support for github/enterprise, gitlab and bitbucket.