cursor: add command /commit

Author: hitzhangjie

.cursor/commands/commit.md

@@ -0,0 +1,8 @@
+# commit
+
+`/commit [message]` is a command to commit the changes to the repo. 
+
+It will commit the changes to the repo with the message "commit message".
+If no message is provided, it will call `git diff --cached` to get the changes, then summarize them into a message.
+
+This command will be available in chat with /commit