The automation state trigger has deprecated its state alias (#2758)

The "state" used to be an alias for "to" but this was deprecated to make the
meaning more clear.

This commit updates the examples to no longer use the deprecated name.

source/_cookbook/automation_for_rainy_days.markdown

@@ -20,7 +20,7 @@ automation:
     trigger:
       - platform: state
         entity_id: sensor.precip_intensity
-        state: 'rain'
+        to: 'rain'
     condition:
       - platform: state
         entity_id: group.all_devices
@@ -40,7 +40,7 @@ And then of course turn off the lamp when it stops raining but only if it's with
     trigger:
       - platform: state
         entity_id: sensor.precip_intensity
-        state: 'None'
+        to: 'None'
     condition:
       - condition: sun
         after: 'sunset'