Review synopsis, description, and examples for handwritten cmdlets

[peombwa]

Some of the help files added as part of #2307 have placeholder synopsis, description, and examples for handwritten cmdlets. The feature shouldn't ship with placeholder values. The descriptions can be found in the C# cmdlet code and their associated PRs -

msgraph-sdk-powershell/src/Authentication/Authentication/Cmdlets/Environment/AddMgEnvironment.cs

Line 17 in 69f727b

/// Adds Microsoft Graph environment to the settings file.

and #425

cc\ @timayabi2020