Updated changelog

Author: Orange-Murker

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
  - Fix transmission termination in I2C master DMA read [#736]
  - Prevent starting a new I2C transmission before previous stop finishes [#737]
+ - Fix complementary output polarity for PWM [#754]
 
 ## [v0.20.0] - 2024-01-14