Clarified docs on comma in trailing return type

docs/CookBook.md

@@ -940,8 +940,18 @@ void a_test()
 
 ### <A name="mocking_return_template"/> Mocking functions which return a template
 
-To use template as return type you have to put the signature into parentheses
-like this:
+To use template as return type, you need to introduce an alias for the return type instead:
+
+```Cpp
+using pair_ints = std::pair<int,int>;
+
+struct M
+{
+    MAKE_MOCK(make, auto (int, int)->pair_ints);
+};
+```
+If you use the [**`MAKE_MOCKn()`**](reference.md/#MAKE_MOCKn) macros, you can get away
+with enclosing the return type in parentheses, like this:
 
 ```Cpp
 struct M

docs/FAQ.md

@@ -696,23 +696,15 @@ work poorly with templates. It sees the parameters to the
 macro above as `make`, `std::pair<int`, followed by `int>(int,int)`, which
 of course is nonsense and causes compilation errors.
 
-One easy way around this is to put the signature into parentheses:
-
-```Cpp
-struct M
-{
-  MAKE_MOCK2(make, (std::pair<int,int>(int,int)));
-};
-```
-
-Or if you prefer the legacy way, create an alias:
+One easy way around this is to create an alias:
 
 ```Cpp
 using pair_int_int = std::pair<int,int>;
 
 struct M
 {
   MAKE_MOCK2(make, pair_int_int(int,int));
+  MAKE_MOCK(make_trail, auto (int, int)->pair_int_int);
 };
 ```
 
@@ -738,7 +730,7 @@ struct M
 work poorly with templates. The expansion of the
 [**`MAKE_MOCK()`**](reference.md/#MAKE_MOCK) macro sees the parameters to the
 function as `std::pair<int`, followed by `int>`, which  of course is nonsense
-and  causes compilation errors.
+and  causes compilation errors. The same problem applies to the return type.
 
 A way around this is to create an alias: