remove accidentally added Makefile

docs/Makefile

@@ -1,11 +0,0 @@
-
-.PHONY: docs-copy
-docs-copy:
-	mkdir -p hugo/content/; \
-	cd hugo; \
-	git init; \
-	git remote rm origin; \
-	git remote add origin https://github.com/owncloud/owncloud.github.io; \
-	git fetch --depth=1; \
-	git checkout origin/source -f; \
-	rsync -ax --delete --exclude hugo/ --exclude Makefile ../. content/; \