linting, remove trace of mxgraph submodule

.gitmodules

@@ -1,6 +1,3 @@
-[submodule "vendor/mxgraph"]
-	path = src/mxgraph
-	url = https://github.com/jgraph/mxgraph.git
 [submodule "src/drawio"]
 	path = src/drawio
 	url = https://github.com/jgraph/drawio.git

src/editor.ts

@@ -56,7 +56,7 @@ const DEFAULT_EMBED_PARAMS = {
   gapi: 0, // google
   od: 0, // onedrive
   trello: 0, // trello
-  noExitBtn: 1
+  noExitBtn: 1,
 };
 
 const DEFAULT_CONFIG = {