Function find

find<V>(): Sink<V, Optional<V>>
Creates a sink retrieving the first item of the feed.

Consumption stops at the first item, leaving the rest of the feed unconsumed; the first item meeting a condition is retrieved by drawing from a filter() upstream.

An empty feed resolves to undefined; callers wanting a default supply it with ??, and those requiring a value reach for seek instead.
Note
- Incremental: a single item is drawn, so an infinite feed completes.
- Streaming: the item is handed back as it is drawn, none retained.
- Stateless: the outcome rests on the first item alone.
Type Parameters
- V
  The type of items in the feed
Returns Sink<V, Optional<V>>
A sink resolving to the first item of the feed, or to undefined if the feed carries none
Example
```
await pipe(
  (items([1, 2, 3, 4, 5]))
  (find())
);  // 1

await pipe(
  (items([1, 2, 3, 4, 5]))
  (filter(n => n > 3))
  (find())
);  // 4
```
- Defined in sinks/find.ts:55