chore: add kcl 0.8 changelog

Signed-off-by: peefy <xpf6677@163.com>

Author: Peefy

CHANGELOG.md

@@ -1,6 +1,6 @@
 # KCL Changelog
 
-- KCL v0.7.1 - https://github.com/kcl-lang/kcl/releases/tag/v0.7.1
+- KCL v0.8.0 - https://github.com/kcl-lang/kcl/releases/tag/v0.8.0
 - KCL v0.7.0 - https://github.com/kcl-lang/kcl/releases/tag/v0.7.0
 - KCL v0.6.0 - https://github.com/kcl-lang/kcl/releases/tag/v0.6.0
 - KCL v0.5.6 - https://github.com/kcl-lang/kcl/releases/tag/v0.5.6