Added missing changelog entries

Author: str4d

Diff for: CHANGELOG.md

@@ -17,6 +17,19 @@ Entries are listed in reverse chronological order.
     they can either move the checks into their own code, or migrate their
     consensus rules to match the RedDSA specification.
 
+## 0.4.0
+
+* Upgrade `rand` to 0.8, `rand_core` to 0.6, and `rand_chacha` to 0.3, together
+  (#55)
+* Migrate to `jubjub 0.6` (#59)
+* Derive `Debug, PartialEq` (#67)
+* Restrict the maximum number of FROST participants to 255 by using `u8` (#66)
+
+## 0.3.0
+
+* Initial support for FROST (Flexible Round-Optimized Schnorr Threshold)
+  signatures.
+
 ## 0.2.2
 
 * Make `batch::Item: Clone + Debug` and add `batch::Item::verify_single`