From charlesreid1

Using Raw HTML

Because it is dumb to add an extension every time you want to add one little thing onto a MediaWiki page... especially on this wiki...

Just enable raw HTML. But whatever you do, don't allow creation of any public accounts.

Add this to LocalSettings.php:

$wgRawHtml = true;

Now use the <html></html> tags to insert raw HTML and have it rendered:

<html>
<blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">Exp 48-49 launches aboard <a href="https://twitter.com/hashtag/Soyuz?src=hash">#Soyuz</a> MS-01 spacecraft beginning 2-day trip and 4-month mission on space station.<a href="https://t.co/xqY7azRTtE">https://t.co/xqY7azRTtE</a></p>— Intl. Space Station (@Space_Station) <a href="https://twitter.com/Space_Station/status/750900913569615872">July 7, 2016</a></blockquote>
<script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
</html>

which becomes: