update changelog to mention update checking

Author: John-Paul-R

changelog.md

@@ -6,6 +6,7 @@
 - fix permissions system not handling "Permissions Only, not OP" correctly (#380)
 - migrate to Server Translations for langfiles (#384)
 - fix server placeholders in MOTD by @arnokeesman
+- use modrinth for update checking, enabling per-mc-version accuracy (#12)
 
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