Motivation: userland is getting several new subdirectories, it would be
too insane to just dump all of that in the guest root filesystem.
To alleviate the cd pain, .profile puts user inside /lkmc by default.
Automatically pick up packages from under packages/ into BR2_EXTERNAL.
Move many subdirectory READMEs into the toplevel and link to toplevel from those subreadmes instead.
Semi automated conversion, in part because Pandoc is kind of buggy for adoc:
Some of the commands were along the lines:
for f in *.md; do pandoc --atx-headers --base-header-level=3 -o ${f%.md}.adoc --wrap=none $f; done
sed -Ei '/\[\[.*\]\]/d' *.adoc
while read -r f; do cat $f; echo; done <f >g
