title: Add "items per page" drop down box in SHOPIFY
body: <p>I'm building a web store on shopify. I want to add a drop down box on a page that displays my products where I can select number of items to display per page (i.e. 25, 50, 100).</p>
  
  <p>Any suggestions on where to start with this and if there are any shortcodes in shopify that will help me do this?</p>