Make the "Continue editing" button a wikiLink

I32d7f8c8fa38c9f334c3ea28e96d4d83a9f5fe6e highlights that the "Continue
editing" button on the "pre-edit v2" variant of the experiment wasn't
completely defined.

If anything, it's a wikiLink button.

Change-Id: I2ce43cdf079937266dafed592df8facd59682650