Add guidance on identifying conflicting assemblies in CS0433 compiler error documentation (#47379)

* Initial plan

* Add guidance on identifying conflicting assemblies in CS0433 error

Co-authored-by: BillWagner <493969+BillWagner@users.noreply.github.com>

* Move "How to identify conflicting assemblies" section after "This error can also occur if" section

Co-authored-by: gewarren <24882762+gewarren@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: BillWagner <493969+BillWagner@users.noreply.github.com>
Co-authored-by: gewarren <24882762+gewarren@users.noreply.github.com>

Author: 3 people

docs/csharp/language-reference/compiler-messages/cs0433.md

@@ -20,6 +20,16 @@ This error can also occur if:
 
 * The `@ Page` directive has a `CodeFile` attribute when it should be a `CodeBehind` attribute.
 * Code is placed in an *App_Code* folder that shouldn't reside there.
+
+## How to identify the conflicting assemblies
+
+The full error message shows which assemblies contain the conflicting type. The message format is:
+
+```
+error CS0433: The type 'N.C' exists in both 'A, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' and 'B, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'
+```
+
+In this example, the conflicting assemblies are **A** and **B**. The assembly names appear in single quotes before the version information. Use these assembly names to determine which references are causing the conflict and decide how to resolve it.
 
 ## Examples