Un-hide language extensions on the extensions registry direct link to language extensions

Created by: Joelkw

https://sourcegraph.com/extensions?query=category%3A%22Programming+languages%22 takes you to

But it should take you to

We need to just make it so "show more extensions" doesn't hide the actual extensions if the url has the direct category query in it.

This bug arose in #15927 and this link is useful for direct-linking interested parties to the languages supported.