ekncontent: add autogen.sh
ekncontent: add autogen.sh

Won't be needed for a normal build of eos-knowledge-lib, but useful
for building ekncontent as a standalone library
https://phabricator.endlessm.com/T15257

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib