Add SFR Box integration

source/_integrations/sfr_box.markdown

@@ -0,0 +1,23 @@
+---
+title: SFR Box
+description: Instructions on how to integrate SFR Box into Home Assistant.
+ha_category:
+  - Sensor
+ha_release: 2023.2
+ha_iot_class: Local Polling
+ha_config_flow: true
+ha_codeowners:
+  - '@epenet'
+ha_domain: sfr_box
+ha_platforms:
+  - sensor
+ha_integration_type: device
+---
+
+The SFR Box integration offers integration with the **SFR** broadband router.
+
+This integration provides the following platforms:
+
+- Sensors - such as ADSL line status, attenuation, noise and data rate.
+
+{% include integrations/config_flow.md %}