[btcsuite/btcd] 7246b9: docs: Correct JSON-RPC API overview return links.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcd
  Commit: 7246b9b933ff7f7d6ba5fe015e67ee3dbcb3d16c
      
https://github.com/btcsuite/btcd/commit/7246b9b933ff7f7d6ba5fe015e67ee3dbcb3d16c
  Author: Dave Collins <da...@conformal.com>
  Date:   2015-07-20 (Mon, 20 Jul 2015)

  Changed paths:
    M docs/json_rpc_api.md

  Log Message:
  -----------
  docs: Correct JSON-RPC API overview return links.

This commit corrects the JSON-RPC API doc return to overview links for
the Websocket Extension Method Details section.