[FEATURE] Index GitHub Events to the Metrics cluster

[bshien]

Is your feature request related to a problem?

Coming from #75

In order to index data about maintainer_engagement, there first needs to be GitHub Events indexed into the Metrics cluster.

What solution would you like?

There should be an index in the Metrics cluster called github_events that has documents representing GitHub Events created in the OpenSearch project.

Using a GitHub App, listen on GitHub Events created by the opensearch-project organization. Index a document for each event with these fields:

{
  id, // Unique identifier for the event.
  type, // The type of event.
  actor.login, // The username of the actor that triggered the event.
  repo.name, // The name of the repository.
  created_at // The date and time the event was triggered.
  payload.action // The action that was performed(opened, edited, closed, etc.)
}

Document will look like:

{
    "id": "2038382333",
    "type": "IssuesEvent",
    "action": "edited",
    "actor": "bshien",
    "repository": "opensearch-metrics",
    "created_at": "2024-08-27T00:31:56Z"
}

What alternatives have you considered?

An alternative is using the GitHub Events API to query past Events, but because it is a pull-based system, it is not trivial to add only new Events that have not already been indexed into the cluster.

Do you have any additional context?

#57