Update documentation for host/fileset/fileset template cmdlets

[chriswahl]

Is your feature request related to a problem? Please describe.

• Review the Help and Examples for New-RubrikHost to offer more information on how this cmdlet works and more context as to what IDs are being consumed / leveraged by the cmdlet.
• Review the Help and Examples for all Fileset related functions (this confuses people frequently)

Describe the solution you'd like

A clear and concise description of how to use Fileset Templates and Hosts to generate new, unique Filesets for those hosts.

More Examples on generating different Fileset Templates, perhaps with platform specific use cases (Windows, *nix).

Additional context

A brand new admin that has never before used Filesets / Fileset Templates / Hosts should be able to easily understand how these functions work and how to get started with them.

[jaapbrasser]

Fixed in #590