Website: add netlify.toml

[clemyan]

What's the problem this PR addresses?

Some Netlify settings are unclear because they are set through Netlify UI

How did you fix it?

Created a netlify.toml to capture these settings

Checklist

• [x] I have read the Contributing Guide.

• [x] I have set the packages that need to be released for my changes to be effective.

• [x] I will check that all automated PR checks pass before the PR gets reviewed.