Add Match component and package

[thetarnav]

Control-flow component for matching discriminated union (tagged union) members.

type MyUnion = {
  kind: 'foo',
  foo:  'foo-value',
} | {
  kind: 'bar',
  bar:  'bar-value',
}

const [value, setValue] = createSignal<MyUnion>({kind: 'foo', foo: 'foo-value'})
 
<Match on={value()} case={{
  foo: v => <>{v().foo}</>,
  bar: v => <>{v().bar}</>,
}} />

[changeset-bot]

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Latest commit: 075ecce

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[chiefcll]

Any progress on releasing this? I'd like to add it to the lightning demo app

[thetarnav]

I'll just release it. If there are any issues—make an issue.