add submodules

.gitmodules

+[submodule "doc_module_vitis"]
+	path = doc_module_vitis
+	url = http://vm09.veremes.net/Documentation/doc_module_vitis.git
+[submodule "doc_module_vmap"]
+	path = doc_module_vmap
+	url = http://vm09.veremes.net/Documentation/doc_module_vmap.git
+[submodule "doc_module_dtnet"]
+	path = doc_module_dtnet
+	url = http://vm09.veremes.net/Documentation/doc_module_dtnet.git
+[submodule "doc_module_gtf"]
+	path = doc_module_gtf
+	url = http://vm09.veremes.net/Documentation/doc_module_gtf.git

doc_module_dtnet @ 2df5660d

+Subproject commit 2df5660d88c3777a24b8d5bb307db2d2e1410b1b

doc_module_gtf @ 84f0b86d

+Subproject commit 84f0b86d9ab5024dffffcb66e5d484676b2d0c1e

doc_module_vitis @ 058f00a7

+Subproject commit 058f00a7ae7d2642b5b8e0a34679011d29f21297

doc_module_vmap @ c9dc1ddf

+Subproject commit c9dc1ddf744c1c7c19413907f2de898a78ca470c