Add help file and update change log

Author: shenshengkafei

src/Resources/Resources/Az.Resources.psd1

@@ -101,7 +101,7 @@ CmdletsToExport = 'Get-AzProviderOperation', 'Remove-AzRoleAssignment',
                'Remove-AzADSpCredential', 'Remove-AzADUser', 
                'Update-AzADApplication', 'Update-AzADServicePrincipal', 
                'Update-AzADUser', 'Remove-AzResourceGroup', 'Get-AzProviderFeature', 
-               'Register-AzProviderFeature', 'Get-AzLocation', 
+               'Register-AzProviderFeature', 'Unregister-AzProviderFeature', 'Get-AzLocation', 
                'Export-AzResourceGroup', 'Get-AzResourceProvider', 
                'Register-AzResourceProvider', 'Unregister-AzResourceProvider', 
                'Get-AzResourceGroupDeployment', 'New-AzResourceGroupDeployment', 

src/Resources/Resources/ChangeLog.md

@@ -18,6 +18,7 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Added 'Unregister-AzResourceProvider' cmdlet.
 * Updated `Get-AzResourceGroupDeploymentOperation` and `Save-AzResourceGroupDeploymentTemplate` to use the SDK.
 
 ## Version 2.2.0

src/Resources/Resources/help/Unregister-AzProviderFeature.md

@@ -0,0 +1,123 @@
+---
+external help file: Microsoft.Azure.PowerShell.Cmdlets.ResourceManager.dll-Help.xml
+Module Name: Az.Resources
+online version:
+schema: 2.0.0
+---
+
+# Unregister-AzProviderFeature
+
+## SYNOPSIS
+{{ Fill in the Synopsis }}
+
+## SYNTAX
+
+```
+Unregister-AzProviderFeature -FeatureName <String> -ProviderNamespace <String>
+ [-DefaultProfile <IAzureContextContainer>] [-WhatIf] [-Confirm] [<CommonParameters>]
+```
+
+## DESCRIPTION
+{{ Fill in the Description }}
+
+## EXAMPLES
+
+### Example 1
+```powershell
+PS C:\> {{ Add example code here }}
+```
+
+{{ Add example description here }}
+
+## PARAMETERS
+
+### -DefaultProfile
+The credentials, account, tenant, and subscription used for communication with Azure.
+
+```yaml
+Type: IAzureContextContainer
+Parameter Sets: (All)
+Aliases: AzContext, AzureRmContext, AzureCredential
+
+Required: False
+Position: Named
+Default value: None
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -FeatureName
+The feature name.
+
+```yaml
+Type: String
+Parameter Sets: (All)
+Aliases:
+
+Required: True
+Position: Named
+Default value: None
+Accept pipeline input: True (ByPropertyName)
+Accept wildcard characters: False
+```
+
+### -ProviderNamespace
+The resource provider namespace.
+
+```yaml
+Type: String
+Parameter Sets: (All)
+Aliases:
+
+Required: True
+Position: Named
+Default value: None
+Accept pipeline input: True (ByPropertyName)
+Accept wildcard characters: False
+```
+
+### -Confirm
+Prompts you for confirmation before running the cmdlet.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: (All)
+Aliases: cf
+
+Required: False
+Position: Named
+Default value: None
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -WhatIf
+Shows what would happen if the cmdlet runs.
+The cmdlet is not run.
+
+```yaml
+Type: SwitchParameter
+Parameter Sets: (All)
+Aliases: wi
+
+Required: False
+Position: Named
+Default value: None
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### CommonParameters
+This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutVariable, -OutBuffer, -PipelineVariable, -Verbose, -WarningAction, and -WarningVariable. For more information, see [about_CommonParameters](http://go.microsoft.com/fwlink/?LinkID=113216).
+
+## INPUTS
+
+### System.String
+
+## OUTPUTS
+
+### Microsoft.Azure.Commands.ResourceManager.Cmdlets.SdkModels.PSProviderFeature
+
+## NOTES
+
+## RELATED LINKS