Update Steam documentation for config flow (#21809)

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

source/_integrations/steam_online.markdown

@@ -3,18 +3,23 @@ title: Steam
 description: Instructions on how to set up Steam sensors in Home Assistant.
 ha_category:
   - Social
+ha_config_flow: true
 ha_iot_class: Cloud Polling
 ha_release: 0.14
 ha_domain: steam_online
 ha_platforms:
   - sensor
+ha_codeowners:
+  - '@tkdrob'
 ha_integration_type: integration
 ha_codeowners:
   - '@tkdrob'
 ha_config_flow: true
 ---
 
-The `steam` sensor platform will allow you to track the online status of public [Steam](https://steamcommunity.com) accounts.
+The Steam integration will allow you to track the online status of public [Steam](https://steamcommunity.com) accounts.
+
+{% include integrations/config_flow.md %}
 
 ## Setup
 
@@ -22,31 +27,6 @@ You need a [free API key](https://steamcommunity.com/dev/apikey) to use the plat
 
 To find an account's 64-bit SteamID on profiles without a custom URL you can check the URL of the profile page, the long string of numbers at the end is the 64-bit SteamID. If the profile has a custom URL you will have to copy the URL into [STEAMID I/O](https://steamid.io/) to find the 64-bit SteamID.
 
-## Configuration
-
-To use Steam in your installation, add the following to your `configuration.yaml` file:
-
-```yaml
-# Example configuration.yaml entry
-sensor:
-  - platform: steam_online
-    api_key: YOUR_API_KEY
-    accounts:
-      - account1
-      - account2
-```
-
-{% configuration %}
-api_key:
-  required: true
-  description: Your API key from [https://steamcommunity.com/dev/apikey](https://steamcommunity.com/dev/apikey).
-  type: string
-accounts:
-  required: true
-  description: List of 64-bit SteamIDs.
-  type: list
-{% endconfiguration %}
-
 ## Examples
 
 If you want to add the accounts to a group for example you will have to use: