Mention DHT22 in addition to DHT11

Also, update dht library version to 1.1.1

hardware/esp8266com/esp8266/doc/reference.md

@@ -204,7 +204,7 @@ Libraries that don't rely on low-level access to AVR registers should work well.
 - [aREST](https://github.com/marcoschwartz/aREST) REST API handler library.
 - [Blynk](https://github.com/blynkkk/blynk-library) - easy IoT framework for Makers (check out the [Kickstarter page](http://tiny.cc/blynk-kick)).
 - [DallasTemperature](https://github.com/milesburton/Arduino-Temperature-Control-Library.git)
-- [DHT11](https://github.com/adafruit/DHT-sensor-library) - Download latest v1.1.0 library and no changes are necessary.  Older versions should initialize DHT as follows: `DHT dht(DHTPIN, DHTTYPE, 15)`
+- [DHT-sensor-library](https://github.com/adafruit/DHT-sensor-library) - Arduino library for the DHT11/DHT22 temperatur and humidity sensors. Download latest v1.1.1 library and no changes are necessary.  Older versions should initialize DHT as follows: `DHT dht(DHTPIN, DHTTYPE, 15)`
 - [NeoPixel](https://github.com/adafruit/Adafruit_NeoPixel) - Adafruit's NeoPixel library, now with support for the ESP8266 (use version 1.0.2 or higher from Arduino's library manager).
 - [NeoPixelBus](https://github.com/Makuna/NeoPixelBus) - Arduino NeoPixel library compatible with ESP8266. Use the "NeoPixelAnimator" branch for ESP8266 to get HSL color support and more.
 - [PubSubClient](https://github.com/Imroy/pubsubclient) MQTT library by @Imroy.