Add instructions for users to create ledger channel

ops/deployments-from-scratch.md

@@ -234,10 +234,12 @@
 
   # TODO
   export BRIDGE_NITRO_ADDRESS=
-  export L1_BRIDGE_MULTIADDR=
-  export L2_BRIDGE_MULTIADDR=
+  export BRIDGE_PEER_ID=
 
-  # Create the required config file:
+  export L1_BRIDGE_MULTIADDR="/dns4/bridge.laconic.com/tcp/3005/p2p/$BRIDGE_PEER_ID"
+  export L2_BRIDGE_MULTIADDR="/dns4/bridge.laconic.com/tcp/3006/p2p/$BRIDGE_PEER_ID"
+
+  # Create the required config file
   cat <<EOF > nitro-node-config.yml
   nitro_l1_chain_url: "wss://sepolia.laconic.com"
   nitro_l2_chain_url: "wss://optimism.laconic.com"