docs/rp2: Add network information to the rp2 quickref.

Some rp2 boards include WiFi, at least with the very popular Pico W and
Pico 2 W.  New users frequently ask how to set up WiFi and are confused
because it's not covered in the quickref.

This commit adds the wlan section, copied and modified with notes from the
ESP32 quickref.

Signed-off-by: Matt Trentini <matt.trentini@gmail.com>

docs/esp32/quickref.rst

@@ -83,30 +83,30 @@ The :class:`network.WLAN` class in the :mod:`network` module::
 
     import network
 
-    wlan = network.WLAN(network.WLAN.IF_STA) # create station interface
-    wlan.active(True)       # activate the interface
-    wlan.scan()             # scan for access points
-    wlan.isconnected()      # check if the station is connected to an AP
+    wlan = network.WLAN()       # create station interface (the default, see below for an access point interface)
+    wlan.active(True)           # activate the interface
+    wlan.scan()                 # scan for access points
+    wlan.isconnected()          # check if the station is connected to an AP
     wlan.connect('ssid', 'key') # connect to an AP
-    wlan.config('mac')      # get the interface's MAC address
-    wlan.ipconfig('addr4')  # get the interface's IPv4 addresses
+    wlan.config('mac')          # get the interface's MAC address
+    wlan.ipconfig('addr4')      # get the interface's IPv4 addresses
 
     ap = network.WLAN(network.WLAN.IF_AP) # create access-point interface
-    ap.config(ssid='ESP-AP') # set the SSID of the access point
-    ap.config(max_clients=10) # set how many clients can connect to the network
-    ap.active(True)         # activate the interface
+    ap.config(ssid='ESP-AP')              # set the SSID of the access point
+    ap.config(max_clients=10)             # set how many clients can connect to the network
+    ap.active(True)                       # activate the interface
 
 A useful function for connecting to your local WiFi network is::
 
     def do_connect():
-        import network
-        wlan = network.WLAN(network.WLAN.IF_STA)
+        import machine, network
+        wlan = network.WLAN()
         wlan.active(True)
         if not wlan.isconnected():
             print('connecting to network...')
             wlan.connect('ssid', 'key')
             while not wlan.isconnected():
-                pass
+                machine.idle()
         print('network config:', wlan.ipconfig('addr4'))
 
 Once the network is established the :mod:`socket <socket>` module can be used