making margin width configurable

[stas00]

Hi, would it be possible to make margin configurable? the hardcoded 20px on both sides is a lot of wasted work-space.

Currently I had to change it manually:

--- toc2/toc2.js.orig   2018-07-06 15:00:27.139881888 -0700
+++ toc2/toc2.js        2018-07-06 15:00:36.359743263 -0700
@@ -224,7 +224,7 @@
     }

     function setNotebookWidth(cfg, st) {
-        var margin = 20;
+        var margin = 5;
         var nb_inner = $('#notebook-container');
         var nb_wrap_w = $('#notebook').width();
         var sidebar = $('#toc-wrapper');

Thank you.