Install guide tweaks (#6536)

* Install guide tweaks

- Moved the guide to a numbered list so it's more clearly step by step
- Moved the power supply warning out, so it doesn't break the list
- Highlighted and broken out the parts that only apply to the image based installs
- Standardised some of the links so none are inline
- HIghlighted that `hassio.local` requires working mDNS
- A few minor wording tweaks

* Update installation.markdown

* Update installation.markdown

* Update installation.markdown

source/hassio/installation.markdown

@@ -9,38 +9,53 @@ sharing: true
 footer: true
 ---
 
-Hass.io images are available for:
+The following will take you through the steps required to install Hass.io.
 
-- Download the appropriate image for your device:
-  - [Raspberry Pi Zero][pi1]
-  - [Raspberry Pi Zero W][pi0-w]
-  - [Raspberry Pi 1 Model B][pi1]
-  - [Raspberry Pi 2 Model B][pi2]
-  - [Raspberry Pi 3 Model B and B+ 32bit][pi3-32] (recommended)
-  - [Raspberry Pi 3 Model B and B+ 64bit][pi3-64]
-  - [Tinkerboard (Beta)][tinker]
-  - [Odroid-C2 (Beta)][odroid-c2]
-- As [Virtual Appliance]:
-  - [VMDK][vmdk]
+1. Download the appropriate install option:
 
-<p class='note warning'>
-Please remember to ensure you're using an [appropriate power supply](https://www.raspberrypi.org/help/faqs/#powerReqs) with your Pi. Mobile chargers may not be suitable since some were only designed to provide just enough power to the device it was designed for by the manufacturer. **Do not** try to power the Pi from the USB port on a TV, computer, or similar.
-</p>
+   - As an image for your device:
+  
+     - [Raspberry Pi Zero][pi1]
+     - [Raspberry Pi Zero W][pi0-w]
+     - [Raspberry Pi 1 Model B][pi1]
+     - [Raspberry Pi 2 Model B][pi2]
+     - [Raspberry Pi 3 Model B and B+ 32bit][pi3-32]
+     - [Raspberry Pi 3 Model B and B+ 64bit][pi3-64] (beta)
+     - [Tinkerboard (Beta)][tinker]
+     - [Odroid-C2 (Beta)][odroid-c2]
+    
+   - As a virtual appliance: 
+  
+     - [OVA][Virtual Appliance]
+     - [VMDK][vmdk]
+    
+2. Install Hass.io:
 
-- Flash the downloaded image to an SD card using [Etcher][etcher]. We recommend at least a 32 GB SD card to avoid running out of space.
+   - Flash the downloaded image to an SD card using [Etcher][etcher]. We recommend at least a 32 GB SD card to avoid running out of space.
+   - Load the appliance image into your virtual machine software.
 
-- Optional - Setup the WiFi or static IP: On a USB stick, create the `network/my-network` file and follow the [HassOS howto][hassos-network].
-- Insert the SD card (and optional USB stick) into the Raspberry Pi and turn it on. On first boot, it downloads the latest version of Home Assistant which takes ~20 minutes (slower/faster depending on the platform).
+3. Optional - set up the WiFi or static IP: On a USB stick, create the `network/my-network` file and follow the [HassOS howto][hassos-network].
 
-<img src='/images/hassio/screenshots/first-start.png' style='clear: right; border:none; box-shadow: none; float: right; margin-bottom: 12px;' width='150' />
+4. For image based installs insert the SD card (and optional USB stick) into the device.
 
-- You will be able to reach your installation at [http://hassio.local:8123][local].
-- Enable either the [Samba add-on][samba] or the [SSH add-on][ssh] to manage your configuration in `/config/` (From the UI choose **Hass.io** which is located in the sidebar).
+5. Turn on your device or virtual appliance. On first boot, it downloads the latest version of Home Assistant which takes around 20 minutes (slower/faster depending on the platform and your Internet connection).
+
+   <img src='/images/hassio/screenshots/first-start.png' style='clear: right; border:none; box-shadow: none; float: right; margin-bottom: 12px;' width='150' />
+
+6. You will be able to reach your installation at [http://hassio.local:8123][local] (if your router supports mDNS, otherwise see below).
+
+7. Enable either the [Samba add-on][samba] or the [SSH add-on][ssh] to manage your configuration in `/config/` (From the UI choose **Hass.io** which is located in the sidebar).
 
 <p class='note'>
 If your router doesn't support mDNS, then you'll have to use the IP address of your Pi instead of `hassio.local`. For example, `http://192.168.0.9:8123`. You should be able to find the IP address of your Pi from the admin interface of your router.
 </p>
 
+<p class='note warning'>
+If you are using a Raspberry Pi please remember to ensure you're using an [appropriate power supply][pi-power] with your Pi. Mobile chargers may not be suitable since some were only designed to provide just enough power to the device it was designed for by the manufacturer. **Do not** try to power the Pi from the USB port on a TV, computer, or similar.
+</p>
+
+Now you can [configure][configure] your install.
+
 ### {% linkable_title Migrating from a non-Hass.io install %}
 
 If you copy over your existing Home Assistant configuration, make sure to enable the Hass.io panel by adding either `discovery:` or `hassio:` to your configuration.
@@ -72,7 +87,7 @@ $ curl -sL https://raw.githubusercontent.com/home-assistant/hassio-build/master/
 When you use this installation method, the core SSH add-on may not function correctly. If that happens, use the community SSH add-on. Some of the documentation might not work for your installation either.
 </p>
 
-A detailed guide about running Hass.io as a virtual machine is available in the [blog](/blog/2017/11/29/hassio-virtual-machine/).
+A detailed guide about running Hass.io as a virtual machine is available in the [blog][hassio-vm].
 
 [etcher]: https://etcher.io/
 [Virtual Appliance]: https://github.com/home-assistant/hassos/blob/dev/Documentation/boards/ova.md
@@ -89,3 +104,6 @@ A detailed guide about running Hass.io as a virtual machine is available in the
 [local]: http://hassio.local:8123
 [samba]: /addons/samba/
 [ssh]: /addons/ssh/
+[pi-power]: https://www.raspberrypi.org/help/faqs/#powerReqs
+[hassio-vm]: /blog/2017/11/29/hassio-virtual-machine/
+[configure]: /getting-started/configuration/