New spice inputs for New.pm

New spice inputs for description, source domain, and template group. Option to create a relevancy block.

Connected changes in the spice repo - https://github.com/duckduckgo/zeroclickinfo-spice/pull/1034
I made an issue about this, https://github.com/duckduckgo/p5-app-duckpan/issues/110 -- we should do a little error checking on the input before moving ahead with it. Might be best to do some basic error checking for other inputs too. Like verifying source domain is actually a URL and that the template group is a valid option (perhaps that one we can hold-off on for a bit)