Add missing changelog entries

Author: voodoos

CHANGES.md

@@ -12,6 +12,8 @@ Thu Sep 26 18:48:42 CEST 2024
     - Implement new search-by-type command for searching values by types (#1828)
     - Canonicalize paths in occurrences. This helps deduplicate the results and
       show more user-friendly paths. (#1840)
+    - Fix dot-merlin-reader ignoring `SOURCE_ROOT` and `STDLIB` directives
+      (#1839, #1803)
   + editor modes
     - vim: fix python-3.12 syntax warnings in merlin.py (#1798)
     - vim: Dead code / doc removal for previously deleted MerlinPhrase command (#1804)