How to solve the problem of “please enter a commit message to explain why this merge is necessary” when git merges branches?

resolvent:

1. In case of the above situation, press the “ese” exit key in the upper left corner of the keyboard
2. Enter “: WQ”, pay attention to the colon in English input status, and then press “enter”（ I think this method is good. What does “WQ” mean???Learn Linux operating system command: mandatory write file and exit.)