add guide for prive link resources (#11522)

* add guide for prive link resources

* update example

documentation/development-docs/examples/private-link-resource-example.md

@@ -0,0 +1,101 @@
+## `Prerequisite`
+API for `Get` private link resource and private endpoint connection need to be ready at:
+
+#### Private Link Resource API
+```
+"/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{provider}/{Top-Level-Resource}/{Top-Level-Resource-Name}/privateLinkResources"
+```
+```
+"/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{provider}/{Top-Level-Resource}/{Top-Level-Resource-Name}/privateLinkResources/{PrivateLinkResource-Name}"
+```
+
+#### Private Endpoint Connection API
+```
+"/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{provider}/{Top-Level-Resource}/{Top-Level-Resource-Name}/privateEndpointConnections/{PrivateEndpointConnection-Name}"
+```
+```
+"/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/{provider}/{Top-Level-Resource}/{Top-Level-Resource-Name}/privateEndpointConnections"
+```
+
+## `Code Changes Needed`
+Add corresponding {Provider}, {Top-Level-Resource} and {API-Version} into [ProviderConfiguration.cs](https://github.com/Azure/azure-powershell/blob/master/src/Network/Network/PrivateLinkService/PrivateLinkServiceProvider/ProviderConfiguration.cs#L12)
+in following pattern:
+```
+RegisterConfiguration("{Provider}/{Top-Level-Resource}", "{API-Version}")
+```
+For example:
+```
+RegisterConfiguration("Microsoft.Sql/servers", "2018-06-01-preview")
+```
+if "Private Endpoint Connection API" is not available, provide extra bool parameter 'false'
+```
+RegisterConfiguration("Microsoft.Storage/storageAccounts", "2019-06-01", false)
+```
+
+## `End-To-End Test`
+
+### Item Needed
+
++ Top level resource
+```
+New-Az{Top-Level-Resource} -ResourceGroupName {rg_name} -Name {top_level_resource_name}
+
+$TopLevelResource = Get-Az{Top-Level-Resource} -ResourceGroupName {rg_name} -Name {top_level_resource_name}
+```
+
++ private link resource
+```
+$PrivateLinkResource = Get-AzPrivateLinkResource -PrivateLinkResourceId $TopLevelResource.Id
+```
+
++ subnet config (object in memory)
+```
+$SubnetConfig = New-AzVirtualNetworkSubnetConfig -Name {config_name} -AddressPrefix "11.0.1.0/24"      -PrivateEndpointNetworkPolicies "Disabled"
+```
+
++ virtual network
+```
+New-AzVirtualNetwork -ResourceGroupName {rg_name} -Name {vnet_name} -Location {location} -AddressPrefix "11.0.0.0/16" -Subnet $SubnetConfig
+
+$VNet=Get-AzVirtualNetwork -ResourceGroupName {rg_name} -Name {vnet_name}
+```
+
++ private link service connection (object in memory)
+```
+$PLSConnection = New-AzPrivateLinkServiceConnection -Name {pls_connection_name} -PrivateLinkServiceId $TopLevelResource.Id -GroupId $TopLevelResource.GroupId
+```
+
++ endpoint
+```
+New-AzPrivateEndpoint -ResourceGroupName {rg_name} -Name {endpoint_name} -Location {location} -Subnet $VNet.subnets[0] -PrivateLinkServiceConnection $PLSConnection -ByManualRequest
+```
+
+### step-by-step
+1. Create listed items above
+
+2. To get the connection, if `list` for private endpoint connection was supported,
+```
+$connection = Get-AzPrivateEndpointConnection -PrivateLinkResourceId $TopLevelResource.Id
+```
+
+3. To get the connection, if `list` for private endpoint connection was not supported,
+```
+$TopLevelResource = Get-Az{Top-Level-Resource} -ResourceGroupName {rg_name} -Name {top_level_resource_name}
+
+$ConnectionId = $TopLevelResource.PrivateEndpointConnection[0].Id
+
+$Connection = Get-AzPrivateEndpointConnection -ResourceId $ConnectionId
+```
+
+4. Approve/Deny the connection
+```
+Approve-AzPrivateEndpointConnection -ResourceId $ConnectionId
+
+or
+
+Deny-AzPrivateEndpointConnection -ResourceId $ConnectionId
+```
+
+5. Connection cannot be approved after rejection
+
+6. One top level resource can have maximum 3 private end point connection