Tune stylesheets, video directive, print rules

To enhance webpage printing/pdf generation:
* Add video admonition to replace non-function iframes/embed video.
* Add print media queries to tune the styling
* Limit background to media screen.

Also, use width-content css var as a better breakpoint to the mobile
format.

Signed-off-by: Jorge Marques <[email protected]>

Preserve multi-line at nested parse

Allows to have lists in a description column, for example.

Signed-off-by: Jorge Marques <[email protected]>

Fix unpack error when the doc has no toctree

As stated in issue #17, when a doc without a toctree (single page/all
pages are orphans), the doc build would throw an exception because the
wrong value (an empty string) would be returned by the navigation_tree
method.

Signed-off-by: Jorge Marques <[email protected]>

Add scopy to lut.py, bump version

Signed-off-by: Jorge Marques <[email protected]>

Update filter tree logic, versioned, and aggregate

Always hide other toctrees when on a page included on a toctree.
Squash toctrees without title with the previous toctree
Rework versioned variables, simplify the requirements and allow to be
deployed directly on GitHub multiple versions.
Update symbolic aggregate.

Signed-off-by: Jorge Marques <[email protected]>

Resolve git directive link with tree, bump version

"blob" path does not work for compound branch names at the root path,
e.g.
blob/staging/feature/
so use tree and have GitHub redirecting to "blob" when it's a file.

Signed-off-by: Jorge Marques <[email protected]>

Simplify filtered tree logic, bump version

Always hide other toctrees when on a page included on a toctree.
Do not rely on doctools lut.py anymore, since was confusing having to
update it to affect other repository.
The "topic" entry on the lut.py is now the path to the index.rst page
of the toctree, generally an orphan page, to reduce nesting by one level.

Signed-off-by: Jorge Marques <[email protected]>

Fix gen of repos not in the lut.py, bump version

Signed-off-by: Jorge Marques <[email protected]>

Tune only-dark/light CSS, bump version

Signed-off-by: Jorge Marques <[email protected]>

Bump version

Signed-off-by: Jorge Marques <[email protected]>