title: Extract words from text and create a vector from them
body: <p>Suppose, I have a txt file that contains such text:</p>
  
  <pre><code>Type: fruits
  Title: retail
  Date: 2015-11-10
  Country: UK
  Products:
    apple,
    passion fruit,
    mango
  Documents: NDA
  Export: 2.10
  </code></pre>
  
  <p>I read this file with <code>readLines</code> function. 
  Then, I want to get a vector that looks like this: </p>
  
  <pre><code>x &lt;- c(fruits, apple, passion fruit, mango)
  </code></pre>
  
  <p>So, I want to extract the word after "Type:" and all words between "Products:" and  "Documents:". 
  How can I do this? Thanks!</p>