SqlAGReplica: Update documentation requirement (issue dsccommunity#1033)

CHANGELOG.md

@@ -11,7 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Update resource parameter documentation ([issue #1568](https://github.com/dsccommunity/SqlServerDsc/issues/1568)).
   - Documentation is now published to the GitHub Wiki.
   - Update documentation around design pattern for Group Managed Service
-    Account ([issue #378](https://github.com/dsccommunity/SqlServerDsc/issues/378))
+    Account ([issue #378](https://github.com/dsccommunity/SqlServerDsc/issues/378)).
+- SqlAGReplica
+  - Update documentation with a requirement for SqlServer in certain circumstances
+    ([issue #1033](https://github.com/dsccommunity/SqlServerDsc/issues/1033)).
 
 ## [14.0.0] - 2020-06-12
 

source/DSCResources/DSC_SqlAGReplica/README.md

@@ -9,6 +9,13 @@ Always On Availability Group Replica.
 * Target machine must be running SQL Server Database Engine 2012 or later.
 * 'NT SERVICE\ClusSvc' or 'NT AUTHORITY\SYSTEM' must have the 'Connect SQL',
   'Alter Any Availability Group', and 'View Server State' permissions.
+* There are circumstances where the PowerShell module _SQLPS_ that is install
+  together with SQL Server does not work with all features of this resource.
+  The solution is to install the PowerShell module [_SqlServer_](https://www.powershellgallery.com/packages/SqlServer)
+  from the PowerShell Gallery. The module must be installed in a machine-wide
+  path of `env:PSModulePath` so it is found when LCM runs the DSC resource.
+  This will also make all SqlServerDsc DSC resources use the PowerShell
+  module _SqlServer_ instead of the PowerShell module _SQLPS_.
 
 ## Known issues