Little addition to docs on strong typed identifiers with FetchForWriting

Author: jeremydmiller

docs/events/projections/aggregate-projections.md

@@ -184,6 +184,11 @@ public class Payment
 Just note that for single stream aggregations, your strong typed identifier types will need to wrap either a `Guid` or
 `string` depending on your application's `StreamIdentity`. 
 
+At this point, the `FetchForWriting` and `FetchForLatest` APIs do not directly support strongly typed identifiers and you
+will have to just pass in the wrapped, primitive value like this:
+
+snippet: sample_use_fetch_for_writing_with_strong_typed_identifier
+
 ## Aggregate Creation
 
 ::: tip

src/EventSourcingTests/Aggregation/using_guid_based_strong_typed_id_for_aggregate_identity.cs

@@ -6,6 +6,7 @@
 using EventSourcingTests.Projections;
 using JasperFx.Core;
 using JasperFx.Core.Reflection;
+using Marten;
 using Marten.Events;
 using Marten.Events.Aggregation;
 using Marten.Events.Projections;
@@ -87,6 +88,15 @@ public async Task can_utilize_strong_typed_id_in_with_inline_aggregations()
         payment.State.ShouldBe(PaymentState.Verified);
     }
 
+    #region sample_use_fetch_for_writing_with_strong_typed_identifier
+
+    private async Task use_fetch_for_writing_with_strong_typed_identifier(PaymentId id, IDocumentSession session)
+    {
+        var stream = await session.Events.FetchForWriting<Payment>(id.Value);
+    }
+
+    #endregion
+
     [Fact]
     public async Task can_utilize_strong_typed_id_with_async_aggregation()
     {