Revert "Remove old Makefile"

This reverts commit c259349.

Author: peppelinux

Makefile

@@ -0,0 +1,11 @@
+LIBDIR := lib
+include $(LIBDIR)/main.mk
+
+$(LIBDIR)/main.mk:
+ifneq (,$(shell grep "path *= *$(LIBDIR)" .gitmodules 2>/dev/null))
+	git submodule sync
+	git submodule update $(CLONE_ARGS) --init
+else
+	git clone -q --depth 10 $(CLONE_ARGS) \
+	    -b main https://github.com/martinthomson/i-d-template $(LIBDIR)
+endif