Add TODO

Author: robinheghan

src/Compiler/Outline.gren

@@ -168,6 +168,7 @@ readSourceFile fsPerm { absolute, relative } =
             (\source ->
                 { path = absolute
                 , moduleName =
+                    -- TODO: check if valid module name
                     { relative | extension = "" }
                         |> Path.toPosixString
                         |> String.replace "/" "."