Adds a wrt-init kind of on the model of git init for starting a stub
directory with wrt.json, archives/, publish/, and templates/.
Also starts to tweak POD a bit.
I went and read:
https://pause.perl.org/pause/authenquery?ACTION=pause_namingmodules
Realized I should probably not name this something with an inscrutable
top-level namespace. WRT is still inscrutable, I guess, but at least
it's now under App.
- Renames all modules, fixes tests (such as they are)
- Zaps old t/validate/ stuff