Merge bitcoin/bitcoin#24663: doc, init: add links to doc/cjdns.md

daae28885f doc, init: add links to doc/cjdns.md (Jon Atack)

Pull request description:

  Follow-up to #24555.

ACKs for top commit:
  jessebarton:
    ACK [daae288](daae28885f)

Tree-SHA512: eb8f4324f182f7917ddafa9b88ad753fe8f890c1c883c1342768ed9eac998c422ecd9e998fc977e72e26bc87f6aed295940b522187190481889255c8b2e05311

doc/README.md

@@ -73,6 +73,7 @@ The Bitcoin repo's [root README](/README.md) contains relevant information on th
 - [Assets Attribution](assets-attribution.md)
 - [Assumeutxo design](assumeutxo.md)
 - [bitcoin.conf Configuration File](bitcoin-conf.md)
+- [CJDNS Support](cjdns.md)
 - [Files](files.md)
 - [Fuzz-testing](fuzzing.md)
 - [I2P Support](i2p.md)

src/init.cpp

@@ -444,7 +444,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-asmap=<file>", strprintf("Specify asn mapping used for bucketing of the peers (default: %s). Relative paths will be prefixed by the net-specific datadir location.", DEFAULT_ASMAP_FILENAME), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-bantime=<n>", strprintf("Default duration (in seconds) of manually configured bans (default: %u)", DEFAULT_MISBEHAVING_BANTIME), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-bind=<addr>[:<port>][=onion]", strprintf("Bind to given address and always listen on it (default: 0.0.0.0). Use [host]:port notation for IPv6. Append =onion to tag any incoming connections to that address and port as incoming Tor connections (default: 127.0.0.1:%u=onion, testnet: 127.0.0.1:%u=onion, signet: 127.0.0.1:%u=onion, regtest: 127.0.0.1:%u=onion)", defaultBaseParams->OnionServiceTargetPort(), testnetBaseParams->OnionServiceTargetPort(), signetBaseParams->OnionServiceTargetPort(), regtestBaseParams->OnionServiceTargetPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::CONNECTION);
-    argsman.AddArg("-cjdnsreachable", "If set then this host is configured for CJDNS (connecting to fc00::/8 addresses would lead us to the CJDNS network) (default: 0)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
+    argsman.AddArg("-cjdnsreachable", "If set, then this host is configured for CJDNS (connecting to fc00::/8 addresses would lead us to the CJDNS network, see doc/cjdns.md) (default: 0)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-connect=<ip>", "Connect only to the specified node; -noconnect disables automatic connections (the rules for this peer are the same as for -addnode). This option can be specified multiple times to connect to multiple nodes.", ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::CONNECTION);
     argsman.AddArg("-discover", "Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-dns", strprintf("Allow DNS lookups for -addnode, -seednode and -connect (default: %u)", DEFAULT_NAME_LOOKUP), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);