added html and css editors

codeeditor-app/app.html

@@ -1,11 +1,25 @@
 <div class="flex-vert">
     <div class="flex-shrink section top">
-        code editor
+        <h1>code editor</h1>
+        <window-control>
+            <window-control-connector target="code-editor-container[language='Javascript']" class="active">Javascript</window-control-connector>
+            <window-control-connector target="code-editor-container[language='HTML']">HTML</window-control-connector>
+            <window-control-connector target="code-editor-container[language='CSS']">CSS</window-control-connector>
+        </window-control>
     </div>
     <div class="flex-horiz">
-        <code-editor style="min-width: 50%; max-width: 50%;"></code-editor>
+        <div class="code-editor-containers resize-target flex-vert" style="min-width: 50%; max-width: 50%;">
+            <code-editor-container language="Javascript" dir="vertical">
+            </code-editor-container>
+            
+            <code-editor-container language="HTML" dir="vertical" style="display: none;">
+            </code-editor-container>
+            
+            <code-editor-container language="CSS" dir="vertical" style="display: none;">
+            </code-editor-container>
+        </div>
         <div>
-            <resize-handle></resize-handle>
+            <resize-handle target=".resize-target" dir="horizontal"></resize-handle>
             <output-frame></output-frame>
         </div>
     </div>