adding alt text for banner image

public/editor-files/editor.js

@@ -78,7 +78,7 @@ $(function() {
       name: $("#post-name").val(),
       description: $("#post-description").val(),
       image: $("#post-image").val(),
-      image: $("#post-imagealt").val(),
+      imagealt: $("#post-imagealt").val(),
       body: editor.serialize().content.value,
       category: category,
       slug: $("#post-slug").val(),