again: the "depend" variable must never be used for subprojects
that point to a subdirectory of the main project, because there's
no clean way of handling this in case of error conditions.
make it a submodule under config/submodules/. this is for the
documentation, including static site generator documentation,
and image files (photos).
as of this revision, there are now only those "depend" projects
defined in config/git/, where the destination directory of the
subject is not a subdirectory of the main project, so:
in a subsequest revision, i will mitigate an existing bug whereby
failure of the dependency project leaves the main one still
intact, breaking builds; this revision enables that to be done.
from now on, subproject-to-subdirectory-of-main-project will
be avoided in config/git/; config/submodules/ will be used.
Signed-off-by: Leah Rowe <leah@libreboot.org>