Explain usage in README

README.md

@@ -2,6 +2,18 @@
 
 This -thing- is doing a DHCPv6 INFORMATION-REQUEST, waits for a response and displays it.
 
+## Usage
+
+Pass the interface name as the first parameter:
+
+```
+dhcpv6stateless wlp3s0
+```
+
+## Logging
+
+Logging is handled by [Rust env_logger](https://docs.rs/env_logger/latest/env_logger/).
+
 ## References
 
 - <https://datatracker.ietf.org/doc/html/rfc8415#section-6.1>