Add screenlogic integration documentation (#17010)

Add documentation for Pentair ScreenLogic integration.

source/_integrations/screenlogic.markdown

@@ -0,0 +1,33 @@
+---
+title: "Pentair ScreenLogic"
+description: "Instructions on how to integrate a ScreenLogic gateway within Home Assistant."
+ha_release: "2021.4"
+ha_category:
+    - Hub
+    - Sensor
+    - Binary Sensor
+    - Switch
+    - Water Heater
+ha_iot_class: "Local Polling"
+ha_quality_scale: gold
+ha_config_flow: true
+ha_dhcp: true
+ha_codeowners:
+  - '@dieselrabbit'
+ha_domain: screenlogic
+ha_platforms:
+    - switch
+    - binary_sensor
+    - sensor
+    - water_heater
+---
+
+The Pentair ScreenLogic integration allows you to integrate your Pentair Intellitouch or EasyTouch pool controller with Home Assistant via the [Pentair ScreenLogic](https://www.pentair.com/en-us/products/residential/pool-spa-equipment/pool-automation/screenlogic2_interfaceforintellitouchandeasytouchautomationsystems.html) gateway.
+
+{% include integrations/config_flow.md %}
+
+## Options
+
+ScreenLogic options are set via **Configuration** -> **Integrations** -> **Pentair ScreenLogic** -> **Options**.
+
+* Seconds between scans - How many seconds between each polling of the ScreenLogic gateway.