Simple yet useful bash_profile

1. Copy the content in bash_profile.txt and add it into your .bash_profile in your home folder(Usually you could open with vim ~/.bash_profile). Or you should add it to your .profile under your home folder. Refer to this Why ~/.bash_profile is not getting sourced when opening a terminal?
2. Use source ~/.bash_profile to make it take effect. Then you could use l to see the colorful terminal.

Add a shell script to avoid the copy/paste work.

@Sange