Improve the documentation of the API
## Description
We need to investigate the current status of the API documentation.
- Do we have good API documentation? This includes:
- API reference documentation ([REST](https://docs.gitlab.com/ee/api/api_resources.html) and [GraphQL](https://docs.gitlab.com/ee/api/graphql/reference/))
- API user documentation (the how-to content, e.g. [REST](https://docs.gitlab.com/ee/api/#how-to-use-the-api) vs [GraphQL](https://docs.gitlab.com/ee/api/graphql/getting_started.html))
- What are the biggest problems we have now?
- Are there any low handing fruit opportunities for improvement?
- What are the industry standards that we are not meeting?
Based on these discussions, the following are items to address as part of improving the documentation:
- Automatically generate API documentation.
- Agree on a method to generate docs.
- Convert existing docs to use automation.
- Ensure the API documentation style guides are consistent and up to date.
- Revise API user docs for accuracy/style (need to open an issue to investigate if this is needed).
- Refactor existing API reference docs to meet style guide standards.
- This process might be partially automated when we generate API docs automatically. The remaining work would be manual, for example, to standardize on descriptions.
_Feel free to complete this list with other questions_
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