added ssh key to github code example

Example 1: add ssh key to github

$ ssh-keygen -t rsa -b 4096 -C "[email protected]"

Example 2: what is ssh key in github

$ cd ~/.ssh
$ ls

Example 3: add ssh to github

$ clip < ~/.ssh/id_ed25519.pub
# Copies the contents of the id_ed25519.pub file to your clipboard

Example 4: add ssh key to github

> Enter passphrase (empty for no passphrase): [Type a passphrase]
> Enter same passphrase again: [Type passphrase again]