Add changelog

CHANGELOG.md

@@ -48,6 +48,7 @@
     Bug #6273: Respawning NPCs rotation is inconsistent
     Bug #6282: Laura craft doesn't follow the player character
     Bug #6283: Avis Dorsey follows you after her death
+    Bug #6285: Brush template drawing and terrain selection drawing performance is very bad
     Bug #6289: Keyword search in dialogues expected the text to be all ASCII characters
     Bug #6291: Can't pickup the dead mage's journal from the mysterious hunter mod
     Bug #6302: Teleporting disabled actor breaks its disabled state