Missing support for flutter for web

[bean5]

Probably same problem that dnfield/flutter_svg#173 has.

[sachaarbonel]

@bean5 according to the comments you need to have canvas kit enabled instead of the default Html backend

[bean5]

@sachaarbonel If that's clear in the Readme then I agree that this can be closed. Maybe I missed it or the Readme for updated later.

You can probably close this.