Reshaping repo

The repo is designed for use with an existing builds.sr.ht service.
Besides lacking that, I am more interested in a containerized workflow
powered by a Makefile. Package source code will live in `pkgsrc/`,
packages will be built into `pkg/`, and packaging keys will be
generated into `keys/`.

Alos trimmed the packages down to what I will build.

meta.sr.ht: update API build

*.sr.ht: Enable prometheus multiprocessing mode

meta.sr.ht: upgrade to 0.54.3

meta.sr.ht: upgrade to latest version

meta.sr.ht: upgrade to 0.53.16

meta.sr.ht: drop py3-pystache

meta.sr.ht: upgrade to 0.53.15

*.sr.ht: move nginx files

meta.sr.ht: add py3-dnspython dependency

meta.sr.ht-nginx: add sr.ht-nginx dependency

meta.sr.ht: add -nginx subpackage

meta.sr.ht: overhaul init files

meta.sr.ht: add API service

meta.sr.ht: remove py3-prometheus-client dependency

This comes from py3-srht now

meta.sr.ht: move .billing location

sr.ht/meta.sr.ht: add -billing subpackage

meta.sr.ht: update to latest version

Update all dependency packages

Add zxcvbn to meta.sr.ht dependencies