Add Code examples for the gh commands in Docs & Man page

[Lucifergene]

CLI Feedback

What have you loved?

Most of the stuffs

What was confusing or gave you pause?

The lack of code snippets for the various gh commands. It took me almost half a day to search throughout the internet to find how I can edit a gist with gh, without using the editor. I had to refer to this PR to get my answer: #5408

Are there features you'd like to see added?

gh cli needs to display some examples of the commands in the --help section.

Anything else?

have a nice day!