[IMP] web_dialog_size: add task to roadmap

It is important to let users decide their default dialog size. Some have ultrawide monitors and this module does more harm than benefit.

Here I add such task to roadmap, to avoid forgetting about it.

@Tecnativa

web_dialog_size/README.rst

@@ -43,6 +43,11 @@ If you want to set dialog boxes maximized by default, you need to:
 #. Add a new record with the text *web_dialog_size.default_maximize* in
     the *Key* field and the text *True* in the *Value* field
 
+Known issues / Roadmap
+======================
+
+* Allow setting default dialog size per user.
+
 Bug Tracker
 ===========