Feature request (async): limit() to limit a function concurrency

Is your feature request related to a problem? Please describe.
I find [p-limit](https://www.npmjs.com/package/p-limit) helpful (APIs often limit user concurrency). The async module already has retry, debounce, and pooledMap which are similar.
An API like p-limit in deno-std will be great.
```javascript
import pLimit from 'p-limit';

const limit = pLimit(10);

// only 10 concurrent requests
export const geocodeAddress = limit(async (address: string) => {...})
```