fix out of date rainbird docs (#18039)

- Fix a couple missing times that reference `seconds` instead of `minutes` (users following these instructions as they were will get errors; see https://github.com/home-assistant/core/issues/36214)
- Bring example automation yml format up to date.

source/_integrations/rainbird.markdown

@@ -75,7 +75,8 @@ More complex configuration using all possible features could look like this exam
 rainbird:
   - host: IP_ADDRESS_OF_MODULE
     password: YOUR_PASSWORD
-    trigger_time: 6
+    trigger_time:
+      minutes: 6
     zones:
       1:
         friendly_name: My zone 1
@@ -83,7 +84,8 @@ rainbird:
           minutes: 6
       2:
         friendly_name: My zone 2
-        trigger_time: 2
+        trigger_time:
+          minutes: 2
   - host: IP_ADDRESS_OF_ANOTHER_MODULE
     password: YOUR_ANOTHER_PASSWORD
     trigger_time: 0:06
@@ -126,12 +128,11 @@ The service can be used as part of an automation script. For example:
 automation:
   - alias: "Turn irrigation on"
     trigger:
-      platform: time
+      - platform: time
         at: "5:30:00"
     action:
-      service: rainbird.start_irrigation
-      target:
-        entity_id: switch.sprinkler_1
+      - service: rainbird.start_irrigation
         data:
+          entity_id: switch.sprinkler_1
           duration: 5
 ```