Add "Remarks" and "Examples" headings in C2601 error reference

Author: Rageking8

docs/error-messages/compiler-errors-2/compiler-error-c2601.md

@@ -10,10 +10,14 @@ ms.assetid: 88275582-5f37-45d7-807d-05f06ba00965
 
 > '*function*': local function definitions are illegal
 
+## Remarks
+
 Code tries to define a function within a function.
 
 Or, there may be an extra brace in your source code before the location of the C2601 error.
 
+## Examples
+
 The following sample generates C2601:
 
 ```cpp