title: How to include custom js script in ionic 2
body: <p>I have a bunch of javascript files that I would like to include in my Ionic 2 application. 
  I know if it's added to the index.html file it doesn't get bundled into the build folder. How do I solve this problem?
  I digged around and found scripts-copy but wasn't sure how to go about it because I couldn't find any beginner friendly step by step guide. </p>