remove mathjax autocollapse feature

cms/static/cms/js/require-config.js

@@ -56,7 +56,10 @@
             // When upgrading to 2.6, check if this variable name changed.
             window.MathJax = {
                 menuSettings: {
-                    CHTMLpreview: false
+                    CHTMLpreview: false,
+                    collapsible: true,
+                    autocollapse: false,
+                    explorer: true
                 }
             };
         };
@@ -258,6 +261,7 @@
                             ]
                         }
                     });
+
                     // In order to eliminate all flashing during interactive
                     // preview, it is necessary to set processSectionDelay to 0
                     // (remove delay between input and output phases). This

common/static/common/js/discussion/mathjax_include.js

@@ -46,7 +46,7 @@ if (typeof MathJax === 'undefined') {
     window.MathJax = {
         menuSettings: {
             collapsible: true,
-            autocollapse: true,
+            autocollapse: false,
             explorer: true
         }
     };

common/templates/mathjax_include.html

@@ -80,7 +80,7 @@
     window.MathJax = {
         menuSettings: {
             collapsible: true,
-            autocollapse: true,
+            autocollapse: false,
             explorer: true
         }
     };