Add LW-12 documentation (#5264)

* Add LW-12 documentation

* Address comments

source/_components/light.lw12wifi.markdown

@@ -0,0 +1,45 @@
+---
+layout: page
+title: "Lagute LW-12"
+description: "Instructions on how to setup Lagute LW-12 Wifi LED controller within Home Assistant."
+date: 2018-04-28 08:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+ha_category: Light
+ha_iot_class: "Local Polling"
+logo: lagute.png
+ha_release: 0.71
+---
+
+The `lw12wifi` light platform supports Lagute LW-12 Wifi LED controller.
+
+## {% linkable_title Configuration %}
+
+To enable these lights, add the following lines to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+light:
+  - platform: lw12wifi
+    host: IP_ADDRESS_CONTROLLER
+```
+
+{% configuration %}
+host:
+  description: Host name or IP of LW-12 LED stripe to control.
+  required: true
+  type: string
+port:
+  description: Some firmware versions of the LW-12 controller listen on different ports.
+  required: false
+  type: int
+  default: 5000
+name:
+  description: Name to use in the frontend.
+  required: false
+  type: string
+  default: LW-12 FC
+{% endconfiguration %}
+