docs/release-notes: update release notes

This commit updates the release notes with the new configuration fields
added by the previous commit.

Author: ViktorT-11

docs/release-notes/release-notes-0.13.1.md

@@ -25,6 +25,10 @@
   template and GitHub Actions check to ensure that they are always updated 
   unless the `no-changelog` label is added to the PR.
 
+* [Add tlsextraip & tlsextradomain to
+  conf](https://github.com/lightninglabs/lightning-terminal/pull/778)
+
 # Contributors (Alphabetical Order)
 
-* Elle Mouton
+* Elle Mouton
+* Viktor Tigerström