MDN Web Docs OpenSearch Engine door aminomancer

An MDN search engine with a better icon with context properties so it can be made to look good with both light and dark themes.

Search provider details:
name: MDN Web Docs,
search_url: https://developer.mozilla.org/search,
search_form: https://developer.mozilla.org/search?q={searchTerms},
search_url_get_params: q={searchTerms}