Added vagrant plugin installation notes

This adds notes to the read me based on issue #51
where it was noted how to install vagrant-windows
properly.
Update Box Setup Instructions

This adds the prerequisites to include:
- services
- other setup items already called out

This also adds a note for winrm tool always changing
startup of WinRM service back to Delayed.
Merge pull request #65 from ferventcoder/add-install-readme

Added vagrant plugin installation notes
Merge pull request #66 from ferventcoder/add-winrm-information

Update Box Setup Instructions
Add powershell note to readme
Merge pull request #78 from cleblanc87/master

Add powershell note to readme