feat: Generating changelog.md using github actions!

[itsaviral2609]

This PR will close down the issue #2797 which will generate a chnagelog.md in the root repository of Porter when a release is published!

Tested this on my feature branch with my local forked repo and my branch and made changes suggested by @schristoff and @troy0820 for master branch case!

 + git push origin main
 - git push origin master

 jobs:
  changelog:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3.3.0
        with:
          ref: main
          fetch-depth: 0
          token: ${{ secrets.GH_PAT }}

Replaced master by main as discussed

What issue does it fix

Closes #2797

If there is not an existing issue, please make sure we have context on why this change is needed. See our Contributing Guide for examples of when an existing issue isn't necessary.

Notes for the reviewer

Please review my PR and suggest any changes if any 😄
And apology to @schristoff for making it difficult to review earlier
Thanks for being patient and kind :)

Checklist

• Did you write tests?
• Wrote workflow
• Did you write documentation?
• Did you change porter.yaml or a storage document record? Update the corresponding schema file.
• If this is your first pull request, please add your name to the bottom of our Contributors list. Thank you for making Porter better! 🙇‍♀️

Reviewer Checklist

• Comment with /azp run test-porter-release if a magefile or build script was modified
• Comment with /azp run porter-integration if it's a non-trivial PR

[schristoff]

Should we be using this instead - otherwise looks great!

[itsaviral2609]

@schristoff cool! gonna use this then.

token: ${{ secrets.GITHUB_TOKEN  }}

[itsaviral2609]

@schristoff Made the requested changes :)

[schristoff]

Thank you so much!