title: How to join two string with a new line between them?
body: <p>I have two strings like this:</p>
  
  <pre><code>str1 = "my fav fruit apple"
  str2 = "my fav vegetable carrot"
  </code></pre>
  
  <p>I want to join the two strings to become :</p>
  
  <pre><code>"my fav fruit apple
  my fav vegetable carrot"
  </code></pre>
  
  <p>i.e.: become one string with a new line between them. How to do that?</p>