docs: update CHANGELOG for version 0.8.1 release

Author: nkmr-jp

CHANGELOG.md

@@ -1,5 +1,12 @@
 ## [0.8.1](https://github.com/nkmr-jp/prompt-line/compare/v0.8.0...v0.8.1) (2025-07-16)
 
+### Code Refactoring
+* remove unused statistics types and methods ([f8a7952](https://github.com/nkmr-jp/prompt-line/commit/f8a795291ef5e84277b896f66694a0812bd9871d))
+
+### Maintenance
+
+* configure semantic-release to treat more commit types as patch updates ([55bfabb](https://github.com/nkmr-jp/prompt-line/commit/55bfabbb8dcaf1cb4fe6332126236326094e0ce9))
+
 # [0.8.0](https://github.com/nkmr-jp/prompt-line/compare/v0.7.2...v0.8.0) (2025-07-09)