Hide the Flutter badge widget at import level

[richirisu]

I would like to suggest an alternative way of importing the badges package while avoiding a conflict with the newly added Flutter badge widget.

The idea is to simply hide the Flutter badge widget.

This way you can still use the Badge class name as is. It also helps with having to rewrite your old code because you don't need to use a prefix this way.

import "package:badges/badges.dart";
import "package:flutter/material.dart" hide Badge;

[yadaniyil]

@richirisu this is a great idea, thanks!
@M-ixai-L please test if this works fine and make a PR with updated README.md to let people know that there is an easier way to import badges