Updated ReadMe.md to include some tips/hints (#34)

* Updated ReadMe.md to include some tips/hints

As I've talked with @tyler, it should be clear that since this requires hardware interaction, the module must be installed with high privileges. 
I've also indicated the path to the module as an "hint". I assumed that it will always be the same since it's installed as root (correct me if I'm wrong).

* Update README.md

As @tyler suggested, removed the previously added hint.
Added the `sudo pwsh` before the Install-Module

Author: DanielSSilva

README.md

@@ -60,9 +60,12 @@ a pin based GPIO access library written in C.
 You can grab the latest version of PowerShell IoT by running:
 
 ```powershell
+sudo pwsh
 Install-Module Microsoft.PowerShell.IoT
 ```
 
+Please note that since this module works with Hardware, higher privileges are required (run PowerShell with `sudo`, or as `root` user) 
+
 Then see the section on [running](#running).
 
 If you want to write a module that uses PowerShell IoT, include it in the `RequiredModules` field of your module manifest.