docs: Add DHT to ESP8266 Quick Ref and Tutorial

docs/esp8266/quickref.rst

@@ -291,6 +291,24 @@ For low-level driving of an APA102::
     import esp
     esp.apa102_write(clock_pin, data_pin, rgbi_buf)
 
+DHT driver
+----------
+
+The DHT driver is implemented in software and works on all pins::
+
+    import dht
+    import machine
+
+    d = dht.DHT11(machine.Pin(4))
+    d.measure()
+    d.temperature() # eg. 23 (°C)
+    d.humidity()    # eg. 41 (% RH)
+
+    d = dht.DHT22(machine.Pin(4))
+    d.measure()
+    d.temperature() # eg. 23.6 (°C)
+    d.humidity()    # eg. 41.3 (% RH)
+
 WebREPL (web browser interactive prompt)
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