docs: move GPL-2.0 license text to Docimentation directory

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/COPYING.GPL-2.0-only b/Documentation/licenses/COPYING.GPL-2.0-only
similarity index 100%
rename from COPYING.GPL-2.0-only
rename to Documentation/licenses/COPYING.GPL-2.0-only