[.vimrc] Add key map to comment out your code

Some times you want to add a comment to let who read your code will  understand easier. It is easy way to let every one who read your code know who and what time you did it

This tip will help do that. You just need to add the below code to [ .vimrc]. If you are using Ubuntu like me, the vimrc file will locate at / home/son.nguyen