material.angular.io site stuck at v12.0.0-next.3 and examples broken

[joelkesler]

When browsing the Angular Material site, you can't select v11.2.4. When I do, it reverts to v12.0.0-next.3

Also many of the examples (on the Input page) are broken :(

[Splaktar]

@mmalerba Fixed this a couple hours ago, sorry about the confusion. The v12 preview can be properly found at https://next.material.angular.io/ now.