Added keenetic NDMS2 docs (#3373)

* Added keenetic NDMS2 docs

* Added missing logo

source/_components/device_tracker.keenetic_ndms2.markdown

@@ -0,0 +1,37 @@
+---
+layout: page
+title: "Keenetic NDMS2 Routers"
+description: "Instructions how to integrate Keenetic NDMS2 Routers into Home Assistant."
+date: 2017-09-15 15:40
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: keenetic.png
+ha_category: Presence Detection
+ha_release: 0.54
+---
+
+This component offers presence detection by examining devices connected to a [Keenetic](https://keenetic.net/)
+Router running NDMS2 firmware.
+
+To use a Keenetic router in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+device_tracker:
+  - platform: keenetic_ndms2
+    host: !secret router_ip
+    username: !secret router_username
+    password: !secret router_password
+```
+
+Configuration variables:
+
+- **host** (*Required*): The IP address of your router, e.g. 192.168.1.1.
+- **username** (*Required*): The username to login into the router (user should have read access to web interface of the router).
+- **password** (*Required*): The password for the specified username.
+- **interface** (*Optional*): Ihe internal name of the interface to get devices connected to. Default is 'Home'. For expert users only. 
+
+
+See the [device tracker component page](/components/device_tracker/) for instructions how to configure the people to be tracked.