Add a11y-dark theme (#887)

* Add a11y-dark theme

* rename A11y Dark

lib/constants.js

@@ -49,6 +49,25 @@ export const THEMES = [
       meta: '#555'
     }
   },
+  {
+    id: 'a11y-dark',
+    name: 'A11y Dark',
+    highlights: {
+      background: '#2b2b2b',
+      text: '#f8f8f2',
+      variable: '#00e0e0',
+      attribute: '#abe338',
+      definition: '#ffd700',
+      keyword: '#ffa07a',
+      operator: '#f8f8f2',
+      property: '#abe338',
+      number: '#dcc6e0',
+      string: '#ffd700',
+      comment: '#d4d0ab',
+      meta: '#d4d0ab',
+      tag: '#dcc6e0'
+    }
+  },
   {
     id: 'blackboard',
     name: 'Blackboard',
@@ -471,25 +490,6 @@ export const THEMES = [
       tag: '#f92aad'
     }
   },
-  {
-    id: 'tomorrow-night-bright',
-    name: 'Tomorrow Night',
-    highlights: {
-      background: '#000000',
-      text: '#eaeaea',
-      variable: '#7aa6da',
-      attribute: '#99cc99',
-      definition: '#e78c45',
-      keyword: '#d54e53',
-      operator: '#fff',
-      property: '#99cc99',
-      number: '#a16a94',
-      string: '#e7c547',
-      comment: '#d27b53',
-      meta: '#555',
-      tag: '#d54e53'
-    }
-  },
   {
     id: 'twilight',
     name: 'Twilight',