license: update project name in license text

* Change project name from 'git-commit-generator' to
'git-commit-generator (git-msg)'

Signed-off-by: Qiming Chu <cchuqiming@gmail.com>

Author: Emin017

LICENSE

@@ -68,7 +68,7 @@
 3， 请将如下声明文本放入每个源文件的头部注释中。
 
 Copyright (c) 2025 Emin (Qiming Chu)
-git-commit-generator is licensed under Mulan PSL v2.
+git-commit-generator (git-msg) is licensed under Mulan PSL v2.
 You can use this software according to the terms and conditions of the Mulan
 PSL v2.
 You may obtain a copy of Mulan PSL v2 at:
@@ -181,7 +181,7 @@ iii. Attach the statement to the appropriate annotated syntax at the
 beginning of each source file.
 
 Copyright (c) 2025 Emin (Qiming Chu)
-git-commit-generator is licensed under Mulan PSL v2.
+git-commit-generator (git-msg) is licensed under Mulan PSL v2.
 You can use this software according to the terms and conditions of the Mulan
 PSL v2.
 You may obtain a copy of Mulan PSL v2 at: