Fix for the Wiki of Uni Wien wot Matteo Tommasini

This extension is intended to work on the Wiki of the University of Vienna (Austria) at https://wiki.univie.ac.at/ (login only with account of the University of Vienna).
On load of the page, the extension adds a button on top of the page, allowing the user to toggle (expand/collapse) all FAQs at the same time (per default: all FAQs in each website of the Wiki of the University of Vienna are listed as collapsed (only each question is visible, not the answer), and this renders Ctrl+F impossible to use since it searches only the text of each question and not the corresponding answer while collapsed).
Since the Wiki of the University of Vienna is a custom version of the software Confluence by Atlassian, this same extension (after suitable modification of the manifest.json file) could be possibly easily adapted to provide the same feature described above also for any other custom version of Confluence by Atlassian.