Add (responsible) analytics to the website

[decepulis]

While we'd like to have insight into our audience on videojs.org, we want to be sure to do it in a responsible way:

1. what service should we use? Our first thought was posthog, but that may be too heavy for our needs, both in script size (pagespeed.web.dev is docking us points for it right now) and in its usage of cookies (which can be opted out of btw). Should we consider Fathom, as a lightweight and community-friendly alternative?
2. how do we comply with relevant regulations?
   • privacy policy
   • banner?
   • browser-based GPC/DNT preferences?

why do we need analytics?

No seriously, good question.
For one, videojs.org is about to go into overages on Netlify. It would be good to characterize that traffic.