Add CUPS sensor docs (#1377)

* Add CUPS sensor docs

* Add note

source/_components/sensor.cups.markdown

@@ -0,0 +1,43 @@
+---
+layout: page
+title: "CUPS Sensor"
+description: "Instructions how to integrate CUPS sensors into Home Assistant."
+date: 2016-10-30 12:10
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: cups.png
+ha_category: System Monitoring
+ha_iot_class: "Local Polling"
+ha_release: 0.32
+---
+
+
+The `cups` sensor platform is using the open source printing system [CUPS](https://www.cups.org/) to show details about your printers.
+
+To set up the sensor the "Queue Name" of the printer is needed. The fastest way to get it, is to visit the CUPS webinterface at "http://[IP ADDRESS PRINT SERVER]:631" and go to "Printers".
+
+<p class='img'>
+  <img src='{{site_root}}/images/screenshots/cups-sensor.png' />
+</p>
+
+To enable the CUPS sensor, add the following lines to your `configuration.yaml`:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: cups
+    printers:
+      - C410
+      - C430
+```
+
+Configuration variables:
+
+- **printers** array (*Required*): List of printers to add.
+
+
+<p class='note'>
+You will need to install the `python3-dev` or `python3-devel` and the development files for CUPS (`libcups2-dev` or`cups-devel`) package on your system manually (eg. `sudo apt-get install python3-dev libcups2-dev` or `sudo dnf -y install python3-devel cups-devel`) along with a compiler (`gcc`).
+</p>