[GR-20446] Update Changelog

Author: andrykonchin

CHANGELOG.md

@@ -23,6 +23,7 @@ Compatibility:
 * Disable most `nokogiri` C extension patches when system libraries are not being used (#2693, @aardvark179).
 * Implement `rb_gc_mark_maybe` and `rb_global_variable` to ensure `VALUE` stay live in C extensions (@aardvark179).
 * Implement `rb_imemo_tmpbuf` allocation for `ripper` (@aardvark179).
+* Improve support of `:chomp` keyword argument in `IO` and `StringIO` methods (#2650, @andrykonchin). 
 
 Performance: