[FEATURE] Add CI to check blueprint addition and documentation update

[nathaliellenaa]

Is your feature request related to a problem? Currently when a connector blueprint is added to the ml-commons repo, the list of supported connectors in the documentation website is not automatically updated. This results in outdated list of supported connectors for users. (Ref https://github.com/opensearch-project/documentation-website/pull/9143#issuecomment-2627478103)

What solution would you like? Create a CI check in the ml-commons repository that:

1. Detects if a PR is adding a new connector blueprint
2. Prevents the PR from being merged until a corresponding PR in the documentation-website repository is created to update the connector table