Function tally

tally<In>(countArrayItems?: boolean): Link<In, number>
Returns a running tally of how many items have been emitted from the input source.
```
const ch = Chains.run(
 Chains.From.timestamp({ interval: 100 }),
 Chains.Links.tally()
);

for await (const v of ch) {
  // Produces: 1, 2, 3 ... every 100ms
}
```
This is different than sum which adds up numeric values. By default it adds up individual array items
Type Parameters
- In
Parameters
- countArrayItems: boolean = true
Returns Link<In, number>