[docs] new JSON RPC API docs format

[nickfrosty]

Problem

The JSON RPC API docs are difficult to navigate and consume. It should be easier to see the actual method docs and examples of how to use the method.

Changes

• created a new /api landing page (see picture below)
• creates a new display format in a "side-by-side" style format (picture below of what it looks like)
• each RPC method is segmented out into separate markdown "partial" files (currently living in src/api)
• the RPC methods for http and websocket methods have been moved to different pages
• custom sidebar for each of the /api pages to show only the methods related to the current viewed page (e.g. http or websocket methods)
• verified all recent changes of the JSON RPC page have been implemented into the newly formatted partials
  • verified commits affecting the JSON rpc page up until Jan 18, 2023 (which are all since this PR was opened)
  • history of changes here
• added a description of the space value returned for accounts to the API docs
  • see RPC: Return the data length for get account requests #28421

NOTE:
This updated display method will also pave the way to enable the core docs to have each of the client API docs on the same page, with a client "language" selector the user can use to view all the respective API docs for each client (e.g. JSON RPC via cURL, JavaScript, Rust)

Workflow for adding/updating RPC method doc pages

Making updates to the individual docs for each method will be inside of their respective "partial" MDX file, located in the respective src/api folder. See this example of the getAccountInfo method doc for reference

Each of these markdown "partials" will be linked withing the corresponding api doc page (similar to importing a component in React, per the Docusaurus docs). Here is an example for the getAccountInfo method

Screenshot of the proposed new format:

API home page (located at url /api)

Example of the "side-by-side" view (this example is located at /api/http#getaccountinfo)

Read more "details" component expanded:

[jacobcreech]

There's a number of broken links on the page due to pointing to /api instead of /api/http. Are you not worried about the weird navigation going from /developers, clicking on JSON RPC API from the sidebar and being thrown into a new sidebar?

[nickfrosty]

@jacobcreech Incorrect links have been fixed. Including the final removal of the jsonrpc-api.md file and an outdated reference to an RPC method on the edge docs.
Also corrected the linking to the filters criteria object on 2 pages.

I think the sidebar change is a bit annoying, but the best case. Since the new RPC API sidebar is so large and different, having all of the RPC methods also displayed on the regular developer sidebar would be far too cumbersome. In the future, the developers sidebar will be slimmed down to help minimize the visual page change

[jacobcreech]

Awesome work! In regards to the page switching on us between developers -> RPC, we should consider making RPC API its own thing as part of #29744

Pull request has been modified.

[jacobcreech]

Thanks for the update! Looking forward to seeing how this does

[steviez]

Stumbled upon this today and leaving a note to say I'm a fan of the change!