Fix syntax for TextExtension parameter in example 5

Author: kapsiR

docset/winserver2025-ps/pki/New-SelfSignedCertificate.md

@@ -124,7 +124,7 @@ The certificate expires in one year.
 $params = @{
     Type = 'Custom'
     Subject = 'CN=Patti Fuller,OU=UserAccounts,DC=corp,DC=contoso,DC=com'
-    TextExtension @(
+    TextExtension = @(
         '2.5.29.37={text}1.3.6.1.5.5.7.3.2',
         '2.5.29.17={text}upn=pattifuller@contoso.com' )
     KeyUsage = 'DigitalSignature'