Update change file to include entry for the new C# file-based template.

Author: normj

.autover/changes/e90fda4d-97af-48f4-af11-8c7e794a7076.json

@@ -5,6 +5,7 @@
       "Type": "Major",
       "ChangelogMessages": [
         "Update templates to target .NET 10",
+		"Add new lambda.FileBased template for C# file-based Lambda functions",
 		"Lambda projects will now be created directly in output directory instead of under src/<name>",
 		"Removed xUnit test projects to allow Lambda projects to be created in output directory",
 		"Removed lambda.OrderFlowersChatbot and lambda.LexBookTripSample templates"