Why pull the pin high for 250ms?

In [TinyDHT.cpp](https://github.com/adafruit/TinyDHT/blob/master/TinyDHT.cpp#L87), the `DHT::read` function pulls the data pin high for 250ms:

```c
// pull the pin high and wait 250 milliseconds
digitalWrite(_pin, HIGH);
delay(250);
```

What is this delay for? Looking through [the data sheet](https://cdn-shop.adafruit.com/datasheets/Digital+humidity+and+temperature+sensor+AM2302.pdf) it doesn't appear to be required.

Start with TinyDHT.cpp at the DHT::read function and compare the 250 ms delay with the linked AM2302 datasheet. Confirm whether the delay is required and identify the intended change or explanation; the issue is done only when that rationale and any resulting action are established.

Written by the indexing model from the issue text.