Add error link to period col error (#1494)

* add error link to period col error

* remove sql server 15 from link

src/Microsoft.SqlTools.ServiceLayer/TableDesigner/Contracts/TableDesignerIssue.cs

@@ -39,5 +39,10 @@ namespace Microsoft.SqlTools.ServiceLayer.TableDesigner.Contracts
         /// The severity of the message. Default value is Error.
         /// </summary>
         public IssueSeverity Severity { get; set; } = IssueSeverity.Error;
+
+        /// <summary>
+        /// Any link to docs associated with error for more information
+        /// </summary>
+        public string MoreInfoLink { get; set; }
     }
 }

src/Microsoft.SqlTools.ServiceLayer/TableDesigner/TableDesignerValidator.cs

@@ -392,7 +392,8 @@ namespace Microsoft.SqlTools.ServiceLayer.TableDesigner
             {
                 errors.Add(new TableDesignerIssue()
                 {
-                    Description = "System versioned table must have the period columns defined."
+                    Description = "System versioned table must have the period columns defined.",
+                    MoreInfoLink = "https://docs.microsoft.com/sql/relational-databases/tables/creating-a-system-versioned-temporal-table"
                 });
             }
             return errors;