Adding User Guide - initial structure

* Added User Guide sections.
* Moved HTTPS example to articles.
* Replaced Hello World example with User Guide.
* Moved use cases out of examples.
* Moved all left over use and examples to articles.
* Fixed a huge number of 404s.
* Re-ordered the menu.

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)