doc: update with electrum info

contrib/lianad_config_example.toml

@@ -29,12 +29,34 @@ main_descriptor = "wsh(or_d(pk([0dd8c6f0/48'/1'/0'/2']tpubDFMbZ7U5k5hEfsttnZTKMm
 network = "testnet"
 poll_interval_secs = 30
 
-# This section is specific to the bitcoind implementation of the Bitcoin backend. This is the only
-# implementation available for now.
+# This section depends on the Bitcoin backend being used.
+#
+# If using bitcoind, the section name is [bitcoind_config].
 # In order to be able to connect to bitcoind, it needs to know on what port it is listening and
 # how to authenticate, either by specifying the cookie location with "cookie_path" or otherwise
 # passing a colon-separated user and password with "auth".
+#
+# With cookie path:
+#
+# [bitcoind_config]
+# addr = "127.0.0.1:18332"
+# cookie_path = "/home/wizardsardine/.bitcoin/testnet3/.cookie"
+#
+# With user and password:
+#
+# [bitcoind_config]
+# addr = "127.0.0.1:18332"
+# auth = "my_user:my_password"
+#
+#
+# If using an Electrum server, the section name is [electrum_config].
+# In order to connect, it needs the address as a string, which can be
+# optionally prefixed with "ssl://" or "tcp://". If omitted, "tcp://"
+# will be assumed.
+# [electrum_config]
+# addr = "127.0.0.1:50001"
+#
+#
 [bitcoind_config]
 addr = "127.0.0.1:18332"
 cookie_path = "/home/wizardsardine/.bitcoin/testnet3/.cookie"
-# auth = "my_user:my_password"

doc/USAGE.md

@@ -77,13 +77,13 @@ fear not! This is just a one time cost. Also, the full node is pruned so it will
 
 Liana can be run as a headless server using the `lianad` program.
 
-As a Bitcoin wallet, Liana needs to be able to connect to the Bitcoin network. The software has been
-developed such as multiple ways to connect to the Bitcoin network may be available. However for now
-only the connection through `bitcoind` is implemented.
+As a Bitcoin wallet, Liana needs to be able to connect to the Bitcoin network,
+which is currently possible through the Bitcoin Core daemon (`bitcoind`) or an Electrum server.
 
-Therefore in order to use Liana you need to have the Bitcoin Core daemon (`bitcoind`) running on your machine for the
-desired network (mainnet, signet, testnet or regtest). The `bitcoind` installation may be pruned (note this may affect block chain
-rescans) up to the maximum (around 550MB of blocks).
+The chosen Bitcoin backend must be available while Liana is running.
+
+If using `bitcoind`, it must be running on your machine for the desired network (mainnet, signet, testnet or regtest)
+and may be pruned (note this may affect block chain rescans) up to the maximum (around 550MB of blocks).
 
 The minimum supported version of Bitcoin Core is `24.0.1` (if you want to use Taproot it's `26.0`).
 If you don't have Bitcoin Core installed on your machine yet, you can download it