docs: v3.3.1 changelog

Author: kozistr

docs/changelogs/v3.3.1.md

@@ -9,4 +9,4 @@
 * Implement `ScheduleFreeRAdam` optimizer. (#304)
 * Implement `LaProp` optimizer. (#304)
     * [Separating Momentum and Adaptivity in Adam](https://arxiv.org/abs/2002.04839)
-* Support `Cautious` variant to `LaProp`, `AdamP`. (#304).
+* Support `Cautious` variant to `LaProp`, `AdamP`, `Adopt` optimizers. (#304).