Update site/Docs/Reference/Package-Manager-Console-PowerShell-Reference.markdown

Formatted  
Install-Package [-Id] <string> [-IgnoreDependencies] [-ProjectName <string>] [-Version 
<string>] [-Source <string>]  




<string>was missing in parameter definitions
Merge pull request #67 from MNF/patch-1

Update site/Docs/Reference/Package-Manager-Console-PowerShell-Reference....