Replaced hidden div for textarea off-the screen

Element with the content being copied cant be hidden so instead i\'ve moved it off the screen

app/assets/stylesheets/pages/snippets.scss

@@ -28,3 +28,11 @@
   border: 1px solid;
   line-height: 32px;
 }
+
+.markdown-snippet-copy {
+  position: fixed;
+  top: -10px;
+  left: -10px;
+  max-height: 0;
+  max-width: 0;
+}

app/views/shared/snippets/_blob.html.haml

 - unless @snippet.content.empty?
   - if markup?(@snippet.file_name)
-    .hidden.blob-content{data: {blob_id: @snippet.id}}
+    %textarea.markdown-snippet-copy.blob-content{data: {blob_id: @snippet.id}}
       = @snippet.data
     .file-content.wiki
       = render_markup(@snippet.file_name, @snippet.data)