Add documentation for Lidarr integration (#21625)

Co-authored-by: Franck Nijhof <frenck@frenck.nl>

source/_integrations/lidarr.markdown

@@ -0,0 +1,29 @@
+---
+title: Lidarr
+description: Instructions on how to integrate Lidarr with Home Assistant
+ha_category:
+  - Downloading
+ha_release: "2022.10"
+ha_iot_class: Local Polling
+ha_domain: lidarr
+ha_config_flow: true
+ha_codeowners:
+  - '@tkdrob'
+ha_quality_scale: silver
+ha_platforms:
+  - sensor
+---
+
+The Lidarr integration pulls data from a given [Lidarr](https://lidarr.audio/) instance.
+
+{% include integrations/config_flow.md %}
+
+To retrieve your API key, open your Lidarr web interface and navigate to Settings, then General tab. Your Lidarr API Key will be listed on this page under the Security section.
+
+## Sensors
+
+The Lidarr integration will add the following sensors:
+
+- Available disk space for each root folder.
+- The number of episodes in the queue.
+- The number of albums still wanted.