Update branch by merging @jcalderone's feedback on local-dev-env-2.

Add local development network Vagrantfile and Documentation

See merge request !81

... if other hypervisors are installed as well.

Co-Authored-By: Jean-Paul Calderone <jean-paul@privatestorage.io>

This updates this MR to the latest base branch (develop) and also
is an experiment on what happens when I merge instead of rebase to
update MRs.

Create documentation artifacts

See merge request !80

Using a copy of the docs artifacts for packing up
should not exhibit the problems from earlier.

Remove user documentation

See merge request !79

Make GitLab CI choose the right build runner

See merge request opensource/PrivateStorageio!78

Fix the empty machines

See merge request opensource/PrivateStorageio!74

morph 1.5.0 fails to build with the golang runtime surrounding it

Merge develop into staging

See merge request opensource/PrivateStorageio!73

Replace nixpkgs overlays with a nixpkgs fork and upgrade to OpenSSL 1.1.1k

Closes #62

See merge request opensource/PrivateStorageio!72