add release please configuration

[baywet]

reflect the following changes https://github.com/microsoftgraph/msgraph-sdk-java/pull/1964 https://github.com/microsoftgraph/msgraph-sdk-java/pull/1946 https://github.com/microsoftgraph/msgraph-sdk-java/pull/1944 https://github.com/microsoftgraph/msgraph-sdk-java/pull/1939

We want:

• [x] release please header file (yaml .github/release-please.yml)
• [x] release please manifest (json .release-please-manifest.json)
• [x] release please config (json release-please-config.json)
• [x] ~release please workflow to trigger on main branch (.github/workflows/release-please.yml)~ Using the release please GitHub app doesn't require this.
• [ ] ~release please secret setup RELEASE_PLEASE_TOKEN~ install the release please GitHub app to the repository
• [x] changelog keep a changelog header and unreleased information to be removed
• [x] contributing to be updated with commit formatting instructions
• [x] version bump script to be deleted (and removed from the weekly generation process)
• [x] files where the version needs to be updated to be ammended with the special comments for release please

[sebastienlevert]

Add full documentation of the release process

[calebkiage]

We don't need to set the RELEASE_PLEASE_TOKEN anymore since we're using a GitHub app. We just need to install the app in a repository. I've deleted the secret from the microsoftgraph/msgraph-sdk-java repository to avoid confusion.

[baywet]

Thanks for the additional information here. FYI I created all the install requests issues with the OSPO (see timeline on this and related issues)