reformat some data on README

[MahmoudMabrok]

• make data as table i.e command, execution as columns

[farhan787]

@MahmoudMabrok thanks for opening this issue,
We'd want to have a separate markdown files for each command that would have its explanation and its output image within it.

The main repository would have these files and directories,

1. screenshots directory
2. commands directory with below files,
   cd.md
   ls.md
   pwd.md
   ....and so on
3. Readme.md file

Readme.md file will contain a list of links to all the commands in the commands directory. You're more than welcome to open a PR for these changes!