Make 'Semantic Info' menu active (not sure why it was disabled)

Author: dpvc

ts/a11y/explorer/ExplorerPool.ts

@@ -170,8 +170,8 @@ const allExplorers: { [options: string]: ExplorerInit } = {
       pool,
       doc.explorerRegions.tooltip3,
       node,
-      (x: HTMLElement) => x.hasAttribute('data-semantic-prefix'),
-      (x: HTMLElement) => x.getAttribute('data-semantic-prefix')
+      (x: HTMLElement) => x.hasAttribute?.('data-semantic-prefix-none'),
+      (x: HTMLElement) => x.getAttribute?.('data-semantic-prefix-none')
     ),
   flame: (
     doc: ExplorerMathDocument,

ts/a11y/explorer/Region.ts

@@ -323,14 +323,18 @@ export class ToolTip extends StringRegion {
       height: 'auto',
       opacity: 1,
       'text-align': 'center',
-      'border-radius': '6px',
+      'border-radius': '4px',
       padding: 0,
       'border-bottom': '1px dotted black',
       position: 'absolute',
       display: 'inline-block',
       'background-color': 'white',
       'z-index': 202,
     },
+    ['.' + ToolTip.className + ' > div']: {
+      'border-radius': 'inherit',
+      padding: '0 2px',
+    }
   });
 }
 

ts/ui/menu/Menu.ts

@@ -831,7 +831,6 @@ export class Menu {
               this.checkbox('Role', 'Role', 'infoRole'),
               this.checkbox('Prefix', 'Prefix', 'infoPrefix'),
             ],
-            true
           ),
           this.rule(),
           this.submenu('Role Description', 'Describe math as', [