Update CHANGELOG for Attaparse engine addition

Author: bact

CHANGELOG.md

@@ -38,7 +38,8 @@ See PR for prompt and details.
 - Reorganize noauto test suite by dependency groups
   (torch, tensorflow, onnx, cython, network) #1290
 - Add BLEU, ROUGE, WER, and CER metrics to pythainlp.benchmarks #1295
-- Add Attaparse engine to dependency parser (`dependency_parsing`, engine="attaparse")
+- Add Attaparse engine to dependency parser
+  (`dependency_parsing`, engine="attaparse") #1303
 - Improved documentation; code cleanup; more tests
 
 ## Version 5.1.2 -> 5.2.0