Allow editing of existing code

[siamkreative]

Right now, the only way to edit code is switching to the text editor.

We should highlight the button icon when the TinyMCE node matches <pre>, then when clicking on that icon, we should retrieve the node content in the textarea.

[siamkreative]

✓ Highlight the button when clicking on a pre element

• Need to retrieve the outerHTML (see the console)