docs: enhance documentation for OAuth2 support in notifiers and configuration examples
docs: enhance documentation on optional comment templates for notifiers and SCM providers
refactor: update secret reference syntax in documentation and examples
feat: update documentation for secret references in configuration and notifiers
Add documentation for annotations, notifiers, observability, operations, and SCM providers
- Created Annotations.md to define the integration contract between pipelines and the relay.
- Added Notifiers.md detailing various notification methods and their configurations.
- Introduced Observability.md outlining endpoints, metrics, logging, and tracing for monitoring.
- Developed Operations.md covering state backends, dead letter queue, configuration hot reload, and security hardening.
- Added SCM provider documentation for Azure DevOps, Bitbucket, GitHub, GitLab, Gitea, and SourceHut.
- Created Quickstart.md for a quick setup guide to get started with GitHub commit status.
- Updated sidebar and footer for improved navigation and links to relevant resources.