Add the ability to search for blog posts by tag names

Our blog posts typically have tags in their metadata, e.g.,

https://github.com/wildfly-security/wildfly-elytron/commit/fb0d2d6b60337851656e1c41ac20948f4cad9e7b#diff-401e2f8328fbfbaba001522df579f5efbcbf31b4848c2b1e91c90392b12e6118R5

However, there isn't a way to actually make use of these tags to search for blog posts on a specific topic.

The Quarkus blog allows users to see the tags on the right hand side of the posts page and users can click on specific tags to filter the posts, as shown here:

https://quarkus.io/blog/

It would be nice to add similar functionality to the Elytron blog.

The source for the Elytron website can be found here:
https://github.com/wildfly-security/wildfly-elytron/tree/develop

The source the Quarkus website can be found here:
https://github.com/quarkusio/quarkusio.github.io