If u are familiar with the unix terminal and the famous .bashrc well that's almost the same.

[user]

        .......

[core]

        autocrlf = input

[alias]

        adda = add --all

        co = commit

        ch = checkout

        st = status

        #log

        l = log --oneline --decorate --graph --branches --remotes -20

        ll = log --oneline --decorate -- graph --stat

        ls = log --oneline --decorate --graph --branches --remotes --simplify-by-decoration

        #list aliases

        alias = !git config --get-regexp 'alias.*' | colrm 1 6 | sed 's/[ ]/ = /'

As u can see u can define an alias like in .bashrc and most important the last command provide all the alias in the config file if reequested with the alias command (as .bashrc).

Thanks to Fabrizio Monti (@delphaber)