Add Devialet Integration (#30035)

* Add Devialet Integration

* tiny tweaks

* Apply suggestions from code review

* Update source/_integrations/devialet.markdown

---------

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

source/_integrations/devialet.markdown

@@ -0,0 +1,40 @@
+---
+title: Devialet
+description: Instructions on how to integrate Devialet devices into Home Assistant.
+ha_category:
+  - Media Player
+ha_release: 2023.11
+ha_iot_class: Local Polling
+ha_config_flow: true
+ha_domain: devialet
+ha_codeowners:
+  - '@westenbergf'
+ha_zeroconf:
+  - diagnostics
+  - media_player
+ha_zeroconf: true
+ha_integration_type: integration
+---
+
+The **Devialet** integration lets you control your [Devialet](https://www.devialet.com) wireless speakers from Home Assistant.
+
+<div class='note'>
+
+- For a stereo setup, only one of the speakers need to be configured.
+- Make sure your Devialet firmware version is 2.16.1 or later. Otherwise, expect functions not to work.
+- Assigning a fixed IP address to your speakers is highly recommended.
+
+</div>
+
+{% include integrations/config_flow.md %}
+
+## Tested models
+
+Known supported devices:
+
+- Phantom I
+- Phantom II
+
+## Turning off the device
+
+The media player `turn off`  button and the service `media_player.turn_off` will turn off all the devices of the designated system. Exiting OFF mode is only possible by pressing a physical button on each device.