As a logged-in user on a test wiki, I want an easy way to turn the desktop improvements off in case I don't like the new changes
- link will display in the sidebar in the following cases:
- Logged-in users on test wikis (with a vector version preference NOT set to Legacy Vector - default state)
- Logged-in users on other wikis (with a vector version preference NOT set to Legacy Vector - non-default state)
- Copy: "Switch to old look"
- Selecting the link will take user to the appearances tab in preferences
- Link should contain a provenance parameter in the query string for tracking clicks (https://wikitech.wikimedia.org/wiki/Provenance)
note: copy should read "switch to old look"