Add Mastodon support for social links

Twitter and Discord are both companies with operations in the US and EU and are therefore accountable and registered. A number of the servers on the list you provided are ran by private individuals or organisations that are registered ‘off the books’ (in obscure third countries with limited transparency requirements). Having to track and administer what is, effectively and literally, several different websites that are operated differently and independently induces more costs than it provides b...