位于分支 ran9er

the modification of `H_keys.zsh` include those:
+ about `Tab`:
    - when current line is blank, type TAB, string “cd " will be put in the line, and the menu of "cd" 's  candidates appeared.
    - when current line is "cd  "(notice that there is two space),  in other words, type TAB SPACE in a blank line, it will be replace with "cd ~", and the menu of named directory's candidates appeared.
    - when current line is "cd --",  it will be replace with "cd +"---- i consider that it was not quite utility

+ about `Enter`:
    - when current line is blank, type ENTER, it will put `ls` in the line, then performance ENTER. so you can just type ENTER instead `l`, `s`, `ENTER`.
    - when current line is `cd .....`, type ENTER, the line will replace this to `cd ../../../../`, then performance ENTER， whether there was how many "."

+ for example:
    - you can type `TAB` `.` `.` `.` `ENTER`, it will performance `cd ../../`