Add discovergy integration documentation (#18850)

* Add discovergy integration documentation

* Implement code review

* Add gas meter support

* Update ha_release

---------

Co-authored-by: Charles Garwood <cgarwood@newdealmultimedia.com>

source/_integrations/discovergy.markdown

@@ -0,0 +1,40 @@
+---
+title: Discovergy
+description: Instructions on how to integrate Discovergy within Home Assistant.
+ha_category:
+  - Energy
+  - Sensor
+ha_release: '2023.7'
+ha_iot_class: Cloud Polling
+ha_codeowners:
+  - '@jpbede'
+ha_domain: discovergy
+ha_config_flow: true
+ha_platforms:
+  - sensor
+---
+
+The `discovergy` integration allows users to integrate their [Discovergy](https://discovergy.com/) smart meters into Home Assistant.
+The integration is using the [official REST API](https://api.discovergy.com/docs/#/) by Discovergy.
+
+The integration supports the following meters within Home Assistant:
+
+- [Electricity meter](#electricity-meter)
+- [Gas meter](#gas-meter)
+
+## Prerequisites
+
+For this integration, you need a Discovergy smart meter, a [Discovergy account](https://my.discovergy.com/) and your credentials.
+
+{% include integrations/config_flow.md %}
+
+## Electricity meter
+
+Sensor entities are being added for current active power usage and the all-time total consumption.
+By default, the sensors for phase-specific current active power usage are disabled.
+
+In case you have a combined meter for consumption and production, the all-time total production is added as well.
+
+## Gas meter
+
+A Sensor entity is being added for total gas consumption.