### Description
We have built a lot of capabilities through the REST API framework within MediaWIki, yet few of our processes are currently documented. While some examples and reference implementations exist, we are receiving feedback form developers across the foundation that they are confused about how to follow our desired standards and how to use the tools that already exist. Although there is still more work to improve overall developer experiences to make the processes themselves more intuitive, documentation is a good starting point for guiding developers through our new systems. Additionally, by documenting our current processes, we are more likely to identify potential areas for improvement.
### Conditions of acceptance
Document the following scenarios:
[x] [[ https://www.mediawiki.org/wiki/API:REST_API/Extensions/Modules | Register an extension API through Module Manager ]]
[] Register an API module for a set of MediaWiki Core endpoints
[] Generating an OpenAPI spec using in-code tags, including examples
[] Defining JSON response examples
[] Register an externally managed API so that it is surfaced in the REST Sandbox
[x] How to run and preview spec changes locally {T399512}
[] Linting processes
[] Spec testing (ie: How to write mocha tests that check for API accuracy)
[] Introduce new API monitoring events & alarms
[] How to use the 'beta' audience designation