https://github.com/FlatRockSoft/Catacomb3D.git added to makefile

diff --git a/16/Catacomb3D b/16/Catacomb3D
new file mode 160000 (submodule)
index 0000000..aa97f49
--- /dev/null
+++ b/16/Catacomb3D
@@ -0,0 +1 @@
+Subproject commit aa97f4995dc7dbea3ecc1794a2d4d4354839cad4