Add error tracking (e.g. Sentry) to the most public frontity projects

Description

Add an error tracking solution to our public frontity projects:


twentytwenty.frontity.org
mars.frontity.org

This will allow us to get information about crashes / errors that normally only happen in users browsers including the full stack traces.

User Stories

As a frontity developer
I want to know when an error happens in a fronitity site when a user visits it
so that I can have better visibility

Details

The free plan has only 1 user and up to 5k events per month
The cheapest Tier is $29 / mo and has 100k events but has a trial period.

It seems that the free plan is good for solo projects, so we can start on the Trial and see how it goes.

Examples

getsentry.com <-- I would recommend this
rollbar.com (Has been tried before on other projects and resulted in a lot of noisy data mostly from ads)