Format all files

[Snapstromegon]

Relates to #1610.

As it was shown in #1668, many files are not correctly formatted as per our current prettier default setup.
This makes it hard to contribute when you try to do everything right by running npm run format before committing.

[zachleat]

We should probably add a precommit hook for this a la https://github.com/11ty/eleventy/blob/8f95fac1c4220d2b19dbc959861cd3d3e3650a21/package.json#L70-L74

[zachleat]

Shipped!