Add Elmax integration documentation. (#20240)

* Add Elmax integration documentation.

* Remove quality scale.

Co-authored-by: Marvin Wichmann <marvin@fam-wichmann.de>

* Update HA_RELEASE version.

Co-authored-by: Marvin Wichmann <marvin@fam-wichmann.de>

* Update source/_integrations/elmax.markdown

Co-authored-by: Marvin Wichmann <marvin@fam-wichmann.de>

* Fix iot_class. Align Elmax naming in a consistent manner.

Co-authored-by: Marvin Wichmann <marvin@fam-wichmann.de>

source/_integrations/elmax.markdown

@@ -0,0 +1,23 @@
+---
+title: Elmax
+description: Instructions on how to integrate Elmax panels within Home Assistant.
+ha_category:
+  - Switch
+ha_release: 2022.2
+ha_iot_class: Cloud Polling
+ha_config_flow: true
+ha_codeowners:
+  - '@albertogeniola'
+ha_domain: elmax
+ha_platforms:
+  - switch
+---
+
+The Elmax integration enables Home Assistant integration with 
+[ELMAX](https://www.elmaxsrl.it/) control panels. Elmax panels are 
+domotic systems focused on intrusion detection and home surveillance.
+
+The current integration is capable of controlling domotic switches 
+and actuators connected to the Elmax panels.
+
+{% include integrations/config_flow.md %}