docs(LICENSE): add appendix
docs(LICENSE): add appendix

turns out GitHub does not register the LICENSE if the APPENDIX is missing,
tested via https://github.com/gr2m/license-test/commit/51ad16b8500ce110df82fd1aa50ac67fb42b1265
hoodiehq/hoodie,davelosert/hoodie,hoodiehq/hoodie,davelosert/hoodie,hoodiehq/hoodie