title: Using checkboxes for variations in WooCommerce to allow multiple choice
body: <p>I've been using WooCommerce for a while now but this one issue is causing me a problem. The client I'm making a site for provides training courses and presentations, and this partiular product (or presentation) allows several different options to be added to the cart, each with its own price.</p>
  
  <p>So, the base price is zero. Then there are 8 different presentations that the user can select via checkbox on their existing website - I somehow need to replicate that using WooCommerce on their new site but I can only use drop downs for variations, and as far as I can see it only allows one option to be chosen. The only feasible way I can see this working is if I add 8 different dropdowns each with all 8 presentations within them and then the customer selects however many different ones they want. This is a bit cumbersome though and potentially can cause user error (selecting the same presentation twice for example).</p>
  
  <p>I have attached a screenshot of what I'd ideally like it to look like within WooCommerce, is there a way this is achievable? I don't mind using plugins if it's the only way.</p>
  
  <p><a href="https://i.stack.imgur.com/VckLs.png" rel="noreferrer"><img src="https://i.stack.imgur.com/VckLs.png" alt="enter image description here"></a></p>