Add Licensed Helper Function Reference

[pauby]

FOSS has a Chocolatey helpers page but while Chocolatey licensed has a link for a page, it doesn't actually exist (see chocolatey.org/docs and scroll down on the left hand side to the bottom of the Paid section).

The following functions are known about and should be added:

• Install-ChocolateyWindowsService
• Uninstall-ChocolateyWindowsService
• Start-ChocolateyWindowsService
• Stop-ChocolateyWindowsService