"context" notation is not supported in iOS < 16.4, and we don't have any
post-processing on our CSS files which can automatically make that
conversion.
For now, changing the stylelint config to enforce the more-compatible
syntax, and updating all occurences.
Stylelint is a css linter: https://stylelint.io/
As part of this change we have added two javascript scripts:
```
pnpm lint:css
pnpm lint:css:fix
```
Look at `.vscode/settings.json.sample` and `.vscode/extensions.json` for
configuration in VSCode.
---------
Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>
