Merge branch 'add-logo-license' into 'develop'

add license to logo

See merge request funkwhale/funkwhale!369

front/src/assets/logo/License.md

+This work is provided under the terms of the Attribution-ShareAlike 4.0 International (CC BY-SA 3.0) license.
+
+The terms of this license can be found here : https://creativecommons.org/licenses/by-sa/4.0/legalcode.
+
+The logo, the favicon and its derivatives were designed by Francis Gading.