[Docs] Onboard release-drafter for release notes

[kavilla]

Is your feature request related to a problem? Please describe.

For the 1.3 release, we had to generate release notes for the build. Our usual process has been checkout on main, install a package, enter the range of commits for that package then the notes will be built. However, since main has commits that cannot go into 1.x and some commits are not the same as the commits on main. So we would have to cross check, the commits from the previous release to the major release to make sure duplication isn't there which is human-error prone. So for 1.3 the PR, we checked out on 1.x, then continued the process.

Then also cleaned up what was generated.

Describe the solution you'd like

Onboard https://github.com/release-drafter/release-drafter, like other @opensearch-project repos, and add the workflow to pull the commits that are labelled for that specific release and add it to a release notes doc.

Describe alternatives you've considered

n/a

Additional context

n/a

[kavilla]

Closing for opensearch-project/.github#156