bitbake: doc: extend classes and include/require documentation

The current documentation is lacking details on the different kinds of
directories for putting classes as well as the order in which BitBake
includes files (classes or include files).

This patch does the following changes:

- Mention the missing classes-recipe and classes-global when applicable.
- Add a Class Types section detailed the three different directories for
  putting classes.
- Move the existing section on locating classes/include files below the
  documentation on the different directives (include/require/inherit).
- Extend the documentation on locating files with include/require and
  inherit to give proper examples, hopefully demystifying this
  mechanism a bit.

[YOCTO #15724]

(Bitbake rev: 7bd36f6c6d33211bb2a6b6fc6d40bdbd83b8b7c3)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions