Adds sample output per issue #1265 (#806)

I added some sample output and an explanation of how the output can vary.
Addresses dotnet/dotnet-api-docs#1265

Author: TashasEv

snippets/visualbasic/VS_Snippets_CLR_System/system.threading.threadlocal/vb/threadlocal.vb

@@ -32,4 +32,14 @@ Module ThreadLocalDemo
         ThreadName.Dispose()
     End Sub
 End Module
-'</snippet01>
+' This multithreading example can produce different outputs for each 'action' invocation and will vary with each run.
+' Therefore, the example output will resemble but may not exactly match the following output (from a 4 core processor):
+' ThreadName = Thread5 
+' ThreadName = Thread6 
+' ThreadName = Thread4 
+' ThreadName = Thread6 (repeat)
+' ThreadName = Thread1 
+' ThreadName = Thread4 (repeat)
+' ThreadName = Thread7 
+' ThreadName = Thread5 (repeat)    
+'</snippet01>