As for this...
How does one figure out which windows feature/package provides a given
PowerShell cmdlet?
... just do this...
# List all available modules
Get-Module -ListAvailable
# Get exported commands in a module
Get-Command -Module '*nfs*'
CommandType Name Version Source
----------- ---- ------- ------
Function Disconnect-NfsSession 1.0 NFS
Function Get-NfsClientConfiguration 1.0 NFS
Function Get-NfsClientgroup 1.0 NFS
Function Get-NfsClientLock 1.0 NFS
...
Update as per you comment
If a given module, as per ...
Get-Module -ListAvailable
.. is not on your machine, not returned by the above command, then anything regarding t will be null/return nothing, thus running the cmdlet ...
Get-Command -Module '*SomeModuleNameFromThePreviousCommand*'
... is really moot.
All module is stored and search for your environment paths.
$env:PSModulePath -split ';'
# Results
<#
C:\Users\...\Documents\WindowsPowerShell\Modules
C:\Program Files\WindowsPowerShell\Modules
C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules
...
#>
$env:Path -split ';'
# Results
<#
...
C:\WINDOWS\System32\WindowsPowerShell\v1.0\
...
C:\Program Files\PowerShell\7\
...
C:\Windows\System32\WindowsPowerShell\v1.0\
...
#>
If you installed a module that does not land there, then you need to tell PowerShell explicitly where it is via the Import-Module cmdlets.
The default installed modules available to all users are here:
C:\Windows\System32\WindowsPowerShell\v1.0\Modules
... which is where you should find the NFS module.
C:\Windows\System32\WindowsPowerShell\v1.0\Modules\NFS