add support for Velbus platform (#2830)

* add support for Velbus platform

* Update light.velbus.markdown

* update and extend documentation to be in line with updated pull request for code

* rename fan example to 'Fan 1'

source/_components/velbus.markdown

@@ -0,0 +1,25 @@
+---
+layout: page
+title: "Velbus"
+description: "Access and control your Velbus devices."
+date: 2017-06-17 16.58
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: velbus.png
+ha_category: Hub
+ha_iot_class: "Local Push"
+ha_release: 0.49
+---
+
+The `velbus` component supports the Velbus USB and Serial gateways.
+
+The gateway needs to be configured by adding the following lines to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+
+velbus:
+  port: '/dev/ttyUSB00'
+```