docs: v2.12.0 changelog

Author: kozistr

docs/changelogs/v2.12.0.md

@@ -9,7 +9,7 @@
 
 ### Docs
 
-* Introduce `mkdocs` with `material` theme.
+* Introduce `mkdocs` with `material` theme. (#204, #206)
     * documentation : https://pytorch-optimizers.readthedocs.io/en/latest/
 
 ### Diff