message: doc: add signet to doc/bitcoin-conf.md
diff: @@ -27,7 +27,7 @@ Comments may appear in two ways:
  ### Network specific options
  Network specific options can be:
  -- placed into sections with headers `[main]` (not `[mainnet]`), `[test]` (not `[testnet]`) or `[regtest]`;
  +- placed into sections with headers `[main]` (not `[mainnet]`), `[test]` (not `[testnet]`), `[signet]` or `[regtest]`;
  - prefixed with a chain name; e.g., `regtest.maxmempool=100`.
  Network specific options take precedence over non-network specific options.
  