Add paperless_ngx docs (#39103)

Co-authored-by: c0ffeeca7 <38767475+c0ffeeca7@users.noreply.github.com>

source/_integrations/paperless_ngx.markdown

@@ -0,0 +1,62 @@
+---
+title: Paperless-ngx
+description: Instructions on how to integrate Paperless-ngx into Home Assistant
+ha_release: 2025.6
+ha_category:
+  - Sensor
+ha_iot_class: Local Polling
+ha_config_flow: true
+ha_domain: paperless_ngx
+ha_codeowners:
+  - '@fvgarrel'
+ha_integration_type: service
+ha_quality_scale: bronze
+related:
+  - url: https://docs.paperless-ngx.com/
+    title: Paperless-ngx
+---
+
+The **Paperless-ngx** {% term integration %} allows you to connect your [Paperless-ngx](https://docs.paperless-ngx.com/) instance to Home Assistant and monitor its status and activity.
+
+## Prerequisites
+
+To ensure full functionality of this integration, you must have **read permissions** for all document-related resources, including documents, tags, document types, and correspondents.
+
+{% details "Create an access token" %}
+
+1. Log in to your **Paperless-ngx** instance.
+2. In the upper-right corner, select your profile icon.
+3. Select **My Profile**.
+4. Under **API Auth Token**, select the right **Refresh** button next to the textbox to generate a new token. Confirm with **yes**.
+5. Copy the token and use it during the integration setup in Home Assistant.
+
+{% enddetails %}
+
+{% include integrations/config_flow.md %}
+
+{% configuration_basic %}
+URL:
+  description: "URL to connect to the Paperless-ngx instance."
+API key:
+  description: "API key to connect to the Paperless-ngx API."
+{% endconfiguration_basic %}
+
+## Sensors
+
+This integration provides {% term sensors %} for the following information from Paperless-ngx:
+
+| Sensor                   | Description                                                              |
+|--------------------------|--------------------------------------------------------------------------|
+| **Correspondents**       | Indicates the total number of defined correspondents.                    |
+| **Document types**       | Indicates the total number of defined document types.                    |
+| **Documents in inbox**   | Indicates the number of documents currently in the inbox.                |
+| **Tags**                 | Indicates the total number of defined tags                               |
+| **Total characters**     | Indicates the total number of characters extracted from all documents.   |
+| **Total documents**      | Indicates the total number of documents stored.                          |
+
+
+## Removing the integration
+
+This integration follows standard integration removal. No extra steps are required.
+
+{% include integrations/remove_device_service.md %}