List more RPC providers and their capabilities and visibility

[BigLep]

Done Criteria

There is a canonical documentation for the various RPC endpoints a builder can potentially use. This documentation lists:

• Operator (company) name
• URLs
• Whether they support:
  • JSON RPC (Common Node API) read operations
  • MPoolPush for sending messages that have already been signed.
  • JSON RPC (Common Node API) write operations
  • ETH RPC read operations
  • ETH RPC write operations
• Documentation link
• Whether endpoint is public or requires authentication/authorization
• If auth is required, where someone goes to request access from the provider.

Why Important

Various teams are putting work into improving the RPC experience for clients by improving the software deployed by RPC servers. It should be self-service discoverable for an app-builder who they can reach out to rely on for building their app.

User/Customer

RPC user
Maintainers so they are cognizant of who is depending on their work

Notes

1. I'm assuming we'd be updating https://docs.filecoin.io/networks/mainnet/rpcs and https://docs.filecoin.io/networks/calibration/rpcs.
2. Idea: a table could capture this information pretty well.
3. This is a good opportunity to do other cleanup like Remove ChainUp from RPC providers #2299

[BigLep]

@eshon : this suggestion came out of discussion in FilOz when @jennijuju, myself, and others from FilOz were thinking about the documentation-related work we'd ideally want accompanying the RPC improvements the team is making. Let us know if:

1. this seems reasonable
2. is potentially something fil-pronto can handle
3. it's useful to talk other places (e.g., #fil-b slack, sync meeting)

Thanks!