Setup uptime monitoring

[simonw]

Following:

• ValueError: Requested 'h11<0.15,>=0.13', but h11==0.12.0 is already installed #56

Need a mechanism that will alert me if the site breaks in the future. I didn't think I'd need this for a static site but it turns out it can still be broken by changes outside my control.

[Lewiscowles1986]

If you used playwright.config.js / ts; I think you could control the server via environment variable...

Then you can default to the values you've hard-coded in tests/test_datasette_lite.py, and change that to also have the same value cascade.

It actually looks like --base-url is an option https://playwright.dev/python/docs/test-runners#configure-base-url for the python pytest wrapper.