Update CHANGELOG.md

paddleaudio/CHANGELOG.md

 # Changelog
 
+Date: 2022-3-15, Author: Xiaojie Chen.
+  - kaldi and librosa mfcc, fbank, spectrogram.
+  - unit test and benchmark.
+
 Date: 2022-2-25, Author: Hui Zhang.
   - Refactor architecture.
-  - dtw distance and mcd style dtw
+  - dtw distance and mcd style dtw.