Update src/webrtc.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/webrtc.rs

@@ -259,6 +259,8 @@ impl WebRTCStream {
     #[inline]
     pub fn set_key(&mut self, _key: Key) {
         // not-supported
+        // WebRTC uses built-in DTLS encryption for secure communication.
+        // DTLS handles key exchange and encryption automatically, so explicit key management is not required.
     }
 
     #[inline]