Remove flags in README

[toastal]

Removing flags in favor of language codes. Flags represent nations, not languages.

Some obviously controversial flags: United Kingdom, Spain, France, Portugal. These examples have more speakers outside the origin country than within and is a very Euro-centric, colonial viewpoint of language to use any flag whatsoever. Not to mention, many countries have more than one language which further propagates stereotypes or belittlement of minority groups inside those countries.