Add documentation page for FutureNow Lights (#5875)

* P5 brand logo

* Documentation page for FutureNow light component

* Documentation page for FutureNow light component

* Documentation page for FutureNow light component

* Documentation update to reflect code fine-tunes. Separated an extended configuration example.

source/_components/light.futurenow.markdown

@@ -0,0 +1,97 @@
+---
+layout: page
+title: "P5 FutureNow Lights"
+description: "Instructions on how to set up P5 FutureNow relay/dimmer units as lights within Home Assistant."
+date: 2018-07-24 15:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: p5.png
+ha_category: Light
+ha_release: 0.75
+---
+
+The `futurenow` light platform allows you to use [P5](http://www.p5.hu) FutureNow relay/dimmer units as lights. Currently supported units: 
+* [FutureNow FNIP-6x2AD](http://www.p5.hu/index.php/products/ethernet-modules/265-fnip-6x2ad) dimmer unit (outputs only)
+* [FutureNow FNIP-8x10A](http://www.p5.hu/index.php/products/ethernet-modules/263-fnip-8x10a) relay unit (outputs only)
+
+### {% linkable_title Configuration Sample %}
+
+To use your FutureNow units, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+light:
+  - platform: futurenow
+    driver: FNIP6x10ad
+    host: 192.168.1.101
+    port: 7078
+    devices:
+      5:
+        name: Dimmer Channel 5
+        dimmable: true
+```
+
+{% configuration %}
+driver:
+  description: "Type of the device. Currently `FNIP6x10ad` or `FNIP8x10a`."
+  required: true
+  type: string
+host:
+  description: "The IP address or hostname of your unit, e.g., `192.168.1.101`."
+  required: true
+  type: string
+port:
+  description: "The TCP port, as set in the unit's settings. Default is `7078`."
+  required: true
+  type: string
+devices:
+  description: "List of output channels to set up as lights."
+  required: true
+  type: map
+  keys:
+    channel_number:
+      description: "Output's (light) properties."
+      required: true
+      type: map
+      keys:
+        name:
+          description: "The name of the light."
+          required: true
+          type: string
+        dimmable:
+          description: "Set to `true` to enable dimming (FNIP6x10ad only)."
+          required: false
+          type: boolean
+          default: false
+{% endconfiguration %}
+
+### {% linkable_title Extended Configuration Sample %}
+
+The following example `configuration.yaml` has two different FutureNow units with multiple channels:
+
+```yaml
+# Example configuration.yaml entry
+light:
+  - platform: futurenow
+    driver: FNIP6x10ad
+    host: 192.168.1.101
+    port: 7078
+    devices:
+      5:
+        name: Dimmer Channel 5
+      6:
+        name: Dimmer Channel 6
+        dimmable: true
+
+  - platform: futurenow
+    driver: FNIP8x10a
+    host: 192.168.1.102
+    port: 7078
+    devices:
+      1:
+        name: Relay Channel 1
+      2:
+        name: Relay Channel 2
+```