turn-howto: fix some links

docs/turn-howto.md

@@ -302,14 +302,14 @@ Here are a few things to try:
 
    (Understanding the output is beyond the scope of this document!)
 
- * You can test your Matrix homeserver TURN setup with https://test.voip.librepush.net/.
+ * You can test your Matrix homeserver TURN setup with <https://test.voip.librepush.net/>.
    Note that this test is not fully reliable yet, so don't be discouraged if
    the test fails.
    [Here](https://github.com/matrix-org/voip-tester) is the github repo of the
    source of the tester, where you can file bug reports.
 
  * There is a WebRTC test tool at
-   https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/. To
+   <https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/>. To
    use it, you will need a username/password for your TURN server. You can
    either: