docs: adapt to Palladium, drop Bitcoin/upstream examples and links

index, features, HOWTO (node requirements, sizes and sync time measured on
Palladium, real startup log, clone URL), environment, peer discovery and
architecture; rpc-interface examples (getinfo, peers, query with real data);
release_process rewritten without tags/PyPI; changelog gets a plm-electrumx
1.0.0 entry above the upstream history. Links point to this repository.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/peer_discovery.rst

@@ -25,7 +25,7 @@ process.  Ideally it should have at least 4 servers that have shown
 commitment to reliable service.
 
 In ElectrumX this is a per-coin property in `lib/coins.py
-<https://github.com/spesmilo/electrumx/blob/master/electrumx/lib/coins.py>`_.
+<https://github.com/palladium-coin/plm-electrumx/blob/main/src/electrumx/lib/coins.py>`_.
 
 
 server.peers.subscribe