use/docs/license will copy the texts contained in branding
package ("notes" one) over to the image's rootdir so these
can be read with ease; otherwise one has to look up the
right package at best (or unpack squashfs, no user can be
really expected to do that just to *read* a *license*).

This was originally profiles/scripts.d/01-copy-license
script from m-p-d; got cut down heavily.

This one has been brewin' for quite a while but has been
completed finally; some tweaks sure can come in later but
it's working.

Please note that it's rather needed for "proper" distros
with specific branding and docs packages prepared for those;
one should use l10n feature most likely too.