docs(cli): document ping, stop, and getblockheader RPCs

[Husteem]

Description and Notes

Adds RPC documentation for ping, stop, and getblockheader endpoints following the established template and tone of getblockchaininfo.md.

Part of #799

How to verify the changes have made

The documentation was verified against the Rust source in floresta-rpc and floresta-cli crates. Field names, return types, and command behavior were cross-referenced with the actual implementation to confirm accuracy.

You can verify by running:

floresta-cli ping
floresta-cli stop
floresta-cli getblockheader <block_hash>

And comparing the output against the documented fields.

Contributor Checklist

• I've followed the contribution guidelines
• I've linked any related issue(s) in the sections above

[moisesPompilio]

This PR is adding the documentation for getblockheader here: #1006, so I think it would be better to remove that from your PR. Also, you forgot to pass this documentation on to floresta-cli and floresta-rpc.

[jaoleal]

Hi, thanks for taking some time on this...

Also, could you separate documentation per-rpc ? that would be 3 commits

[jaoleal]

Suggested change

	### Error Enum `CommandError`
	### Error Enum

[jaoleal]

Suggested change

	### Error Enum `CommandError`
	### Error Enum

[jaoleal]

Suggested change

	### Error Enum `CommandError`
	### Error Enum

[jaoleal]

ping.md is present on both commits

[moisesPompilio]

@Husteem forgot to pass this documentation on to floresta-cli and floresta-rpc.

[Husteem]

@Husteem forgot to pass this documentation on to floresta-cli and floresta-rpc.

my bad, I'll do that.
i will make a PR once I get clarification on my mentioned comment.

[jaoleal]

You forgot to add them to floresta-rpc