Add documentation for OneDrive

source/_integrations/onedrive.markdown

@@ -0,0 +1,57 @@
+---
+title: OneDrive
+description: Instructions on how to setup OneDrive to be used with backups.
+ha_release: 2025.2
+ha_category:
+  - Backup
+ha_iot_class: Cloud Polling
+ha_config_flow: true
+ha_domain: onedrive
+ha_codeowners:
+  - '@zweckj'
+ha_integration_type: service
+---
+
+This integration allows you to use [OneDrive](https://www.microsoft.com/en-us/microsoft-365/onedrive/online-cloud-storage) for use with Home Assistant Backups.
+
+Backups will be created in a folder called `home-assistant\backups` in the `App Folder` of your OneDrive.
+The integration only has access to a application specific `home-assistant` folder in the `App Folder` and cannot access any other parts of your OneDrive.
+
+{% include integrations/config_flow.md %}
+{% configuration_basic %}
+Client ID:
+  description: "Application Id of the app registration to be used with the integration. Uses Home Assistant provided by default."
+Client secret:
+  description: "Application secret for the app registration. Uses Home Assistant provided by default."
+
+{% endconfiguration_basic %}
+
+{% include integrations/option_flow.md %}
+
+## Requested permissions by the integration
+
+The integration will request the following permissions on your OneDrive for the integration to work:
+
+- `Files.ReadWrite.AppFolder`: Grants the application permission to read and write in its own, app-specific folder inside your OneDrive
+- `offline_access`: Grants the application permission to refresh its authentication token without requiring your manual intervention
+- `openid`: Grants the application permission to read basic information, e.g. if you have a OneDrive
+
+## Getting application credentials
+
+This integration comes with a predefined set of [application credentials](https://www.home-assistant.io/integrations/application_credentials/) through Home Assistant account linking. 
+Everything is done in a delegated user context, so nobody will ever have access to your data except you. However, if you want to use your own credentials, 
+follow [this guide](https://learn.microsoft.com/en-us/entra/identity-platform/quickstart-register-app?tabs=certificate) to create your own client ID and secret.
+
+{% note %}
+You will need an Azure tenant with an active Azure subscription to create your own client credentials.
+{% endnote %}
+
+## Known Limitations
+
+- Only personal OneDrives are supported at the moment
+
+## Removing the integration
+
+This integration follows standard integration removal. No extra steps are required.
+
+{% include integrations/remove_device_service.md %}