Add Portainer integration docs

source/_integrations/portainer.markdown

@@ -0,0 +1,53 @@
+---
+title: Portainer
+description: Instructions on how to integrate Portainer containers into Home Assistant.
+ha_category:
+  - Sensor
+ha_release: 2024.12
+ha_iot_class: Local Polling
+ha_config_flow: true
+ha_codeowners:
+  - '@Thomas55555'
+ha_platforms:
+  - sensor
+ha_integration_type: integration
+ha_domain: portainer
+---
+
+The Portainer integration provides connectivity with one or more portainer instances. Currently only Docker containers in your Portainer instance are supported.
+
+In order to use this integration you must get an access token.  Refer to [this guide](https://docs.portainer.io/api/access) for general overview of the process.
+
+{% include integrations/config_flow.md %}
+
+### Installation
+
+
+1. Enter the access token you've got from the guid above. The access token typically looks like this: `ptr_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx`
+
+2. Also enter the URL of the portainer instance. Here are a some valid example URLs:
+   - `https://www.myportainer.com`
+   - `https://192.168.178.99:9443`
+   - `http://192.168.178.99:9000` - legacy
+   - `https://myintranet:9443/portainer`
+
+3. Also choose, if the SSL certificate should be verified.
+
+4. Click **OK**
+
+
+## Entities
+
+Once you have enabled the Portainer integration, you should see the following entities:
+
+### Sensor
+
+The integration will create a sensor for each container running in the portainer instance, which shows the current state of the container.
+
+## Remove integration
+
+This integration can be removed by following these steps:
+
+{% include common-tasks/remove_device_service.md %}
+
+After deleting the integration, go to the portainer instance(s) and remove the access token(s) you have created.