Add GitHub topics in repo meta

[jakub-g]

On repo main page, just below the description of the repo and the URL, you can add topic (tags) describing the repo.

I think you could add webpagetest, web-performance and similar topics.

This allows to explore different tools for similar concept, for example:
https://github.com/topics/webpagetest

[sburnicki]

Thanks for the heads-up! I added a bunch of topics :)