Reviewed by: andy, marck
Differential Revision: https://reviews.freebsd.org/D55587

Reviewed by: andy
Differential Revision: https://reviews.freebsd.org/D53848

Reviewed by: andy
Differential Revision: https://reviews.freebsd.org/D53439

Reviewed by: maxim (mentor)
Approved by: maxim (mentor)
Differential Revision: https://reviews.freebsd.org/D51979

* Allow to build the documentation offline using Hugo
* Fix link problems
* Remove SVN entities
* Fix lang problems to help weblate
* Move all the AsciiDoctor translations to the shared folder to
  help weblate
* Allow the possibility to build each document. For example each
document can be edited in and watched the result in real time in
VS Code or Vim/NeoVim.

Breaking changes:

Eliminate the possibility of building books or articles.
They must be builded at the same time.
This functionality will be restored when version 0.89.0 is in the
repositories in a couple of weeks.

Reviewed by:            dbaio@
Differential Revision:  https://reviews.freebsd.org/D31926

Approved by:	carlavilla

I'm very pleased to announce the release of
our new website and documentation using
the new toolchain with Hugo and AsciiDoctor.

To get more information about the new toolchain
please read the FreeBSD Documentation Project Primer[1],
Hugo docs[2] and AsciiDoctor docs[3].

Acknowledgment:
Benedict Reuschling <bcr@>
Glen Barber <gjb@>
Hiroki Sato <hrs@>
Li-Wen Hsu <lwhsu@>
Sean Chittenden <seanc@>
The FreeBSD Foundation

[1] https://docs.FreeBSD.org/en/books/fdp-primer/
[2] https://gohugo.io/documentation/
[3] https://docs.asciidoctor.org/home/

Approved by:    doceng, core