Split API docs into individual pages

[MattIPv4]

Feature request

Feature description

Currently the API docs are rather cumbersome to read through, being all on a single page. We should split the API docs into a page for each endpoint. A sidebar can then be provided on all the pages that allows for navigation through each endpoint.

The API docs homepage can then become a nice intro page, providing a summary for each endpoint we offer and links out to the pages. Further, it can also house the existing error response documentation.

How the feature is useful

Allows the API docs to be read and navigated far more easily.