Use a flatten directory for all adoc files
This commit reworks how asciidoctor files are processed,
by allowing to structure docs using subdirectories, while
maintaining consistent locations for resources, images, samples,
This works by flattening all adoc files into a resources
directory before processing. It means that while we can
use a directory tree to organize docs, we must make sure
not to use the same file name twice.
This makes it possible to compose files more easily. For
example, the dependency management docs can be read as
a single file, or individual files, or as chapters.
Technically speaking, we could remove the "userguideSinglePage"
task, but it's kept just because it's significantly slower
Reshuffle dependency management docs
This commit reshuffle existing dependency management docs
into the new dependency management chapter. It's worth noting
that there's no new content at this point, nor any effort to
make it consistent. It just moves things around, and there
are still quite a few places where dependency management docs
It doesn't try to fix dead links either.