title: How to edit file content using zsh terminal?
body: <p>I created an empty directory on zsh and added a file 
  called hello.rb by doing the following:</p>
  
  <p><code>echo 'Hello, world.' &gt;hello.rb</code></p>
  
  <p>If I want to make changes in this file using the terminal 
  what's the proper way of doing it without opening the file
  itself using let's say TextEditor?</p>
  
  <p>I want to be able to make changes in the file <code>hello.rb</code> strictly 
  by using my zsh terminal, is this at all possible?</p>