Should I be adding LICENSE info to my ports?

[Charlie Kester]

Today on FreshPorts I see some bulk commits adding LICENSE info to 40+
ports. And I've noticed LICENSE being added in many other recent commits.

But I still don't see anything in the Porter's Handbook about how
maintainers should use this infrastructure in their ports.  

I thought we were waiting on the Handbook, but it seems a lot of people
are proceeding without it.  Should I do likewise?  

(There are now enough examples out there that I *think* I can figure
what to do...)