Add `multiaddr` usage snippet for IP4 and UDS

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

snippets/multiaddr_ex.py

@@ -0,0 +1,11 @@
+from multiaddr import Multiaddr
+# construct from a string
+m1 = Multiaddr("/ip4/127.0.0.1/udp/1234")
+m2 =  Multiaddr("/unix/run/user/1000/sway-ipc.1000.1557.sock")
+for key in m1.protocols():
+    key
+    
+uds_sock_path = Path(m2.values()[0])
+uds_sock_path
+uds_sock_path.is_file()
+uds_sock_path.is_socket()