Updated default.md (#4993)

* Updated default.md

* Returns -> Produces

* default.md - removed not complete definition of default(T)

* operators main page: removed not complete definition of default(T)

Author: pkulikov

docs/csharp/language-reference/keywords/default.md

@@ -18,15 +18,13 @@ ms.author: "wiwagn"
 
 # default (C# Reference)
 
-The `default` keyword.
-
 The `default` keyword can be used in the `switch` statement or in a default value expression:
 
 - [The switch statement](switch.md): Specifies the default label.
 
-- [Default value expressions](../../programming-guide/statements-expressions-operators/default-value-expressions.md): Produces the default value of the type. This will be null for reference types and zero for value types, and the 0 bit pattern for structs.
+- [Default value expressions](../../programming-guide/statements-expressions-operators/default-value-expressions.md): Produces the default value of a type.
 
-## See Also
+## See also
 
  [C# Reference](../index.md)  
  [C# Programming Guide](../../programming-guide/index.md)  

docs/csharp/language-reference/operators/index.md

@@ -58,7 +58,7 @@ C# provides many operators, which are symbols that specify which operations (mat
 
  [unchecked](../../../csharp/language-reference/keywords/unchecked.md) – disables overflow checking for integer operations. This is the default compiler behavior.  
 
- [default(T)](../../../csharp/programming-guide/statements-expressions-operators/default-value-expressions.md) – returns the default value of type T: `null` for reference types, zero for numeric types, and zero/`null` filled in members for struct types.  
+ [default(T)](../../../csharp/programming-guide/statements-expressions-operators/default-value-expressions.md) – produces the default value of type T.  
 
  [delegate](../../../csharp/programming-guide/statements-expressions-operators/anonymous-methods.md) – declares and returns a delegate instance.