Track visits to the downloads.moodle.org/mobile/ page

We need to gather some information about the interest of the users in the downloads.moodle.org/mobile/ page

For example, if they come from a search engine or because the page was linked from a Moodle sites, number of visits per month, etc...

Once MDLSITE-6061 is integrated, that page will point to a PHP script where we'll be able to implement all the required tracking