Document and make GA release process repeatable and reproducible

[dblock]

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

Anyone should be able to run an OpenSearch release via a documented and reproducible process (minus access to signing keys).

Describe the solution you'd like

A document that anyone could follow to produce an OpenSearch alpha/beta/GA release.

• Complete Publish snapshots and release artifacts to maven #20 for each component
• Complete Document building end-to-end bundle #73 for the bundle
• Document the process

Additional context

After a release someone asked where the 1.0.0 tags were. Our release process is not documented and expectations of when such things as tags are done are unclear.

[AMoo-Miki]

As a user, I would prefer to be able to run an OpenSearch release via a documented and reproducible process that uses free and open-source tools.

[dblock]

We've codified and are running the process in 1.2. Watch #567. Let's close this issue when 1.2 is released and we've finished all the steps, made updates to the templates and did a post-mortem.

[bbarani]

Closing this issue as we have documented the process in form of release templates and readme file. Feel free to re-open this issue if you need more information.