Adds a copy link next to the edit link on the main template page
- Opens the a new add templete page with the contents of the existing template in it
- makes sure you don't write over the existing template.

I was making some alternate templates of my custom templates which had only
small changes from the originals and found it silly that I had to click 'edit',
copy the original, go back, click 'add template', then paste. thats why i made
this copy link. Essentially, it's the 'add template' link but fills in the form
with the current template contents for you.