Since the current design holds a reference to a HashMap, the referenced data can never be mutated while the FuzzyFinder widget lives. This is no good. We want to have the following features:

• The data can be updated.
• Assuming the filter hasn't changed, new items get scores calculated and insertion in order (no need to iterate again in full).

The current implementation takes reference to HashMap<K, String>. This is restrictive and unnecessary. We should probably:

• Do away with K - let the client relate results to IDs themselves as necessary.
• Deal with impl Iter<T: AsRef<str>> instead of a restrictive choice of concrete type.

This may simplify also the way in which we solve #4.

Currently, when matching against Foobar, foba would get a good score, but bar foo would not. Be more like fzf.

Allow selection of multiple filtered matches (think fzf -m)

Might solve other issues for free 🥇