add UserPool ID SSM param

We'll use this with out Service Manager products

Author: tmclaugh

stacksets/userpool/stackset.yaml

@@ -59,4 +59,13 @@ Resources:
       Domain: !Ref UserPoolDomainName
       UserPoolId: !Ref UserPool
       CustomDomainConfig:
-        CertificateArn: !Ref SiteCertificate
+        CertificateArn: !Ref SiteCertificate
+
+  # SSM Parameters
+  UserPoolIdSsmParam:
+    Type: AWS::SSM::Parameter
+    Properties:
+      Name: "/org/authnz/UserPoolId"
+      Description: User Pool ID
+      Type: String
+      Value: !Ref UserPool