Improve <system_error> functions page

Author: Rageking8

docs/standard-library/system-error-functions.md

@@ -22,16 +22,20 @@ The `generic_category` object is an implementation of [error_category](../standa
 
 ## <a name="is_error_code_enum_v"></a> is_error_code_enum_v
 
+A helper variable template for the [`is_error_code_enum`](is-error-code-enum-class.md) value.
+
 ```cpp
 template <class T>
-    inline constexpr bool is_error_code_enum_v = is_error_code_enum<T>::value;
+constexpr bool is_error_code_enum_v = is_error_code_enum<T>::value;
 ```
 
 ## <a name="is_error_condition_enum_v"></a> is_error_condition_enum_v
 
+A helper variable template for the [`is_error_condition_enum`](is-error-condition-enum-class.md) value.
+
 ```cpp
 template <class T>
-    inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<T>::value;
+constexpr bool is_error_condition_enum_v = is_error_condition_enum<T>::value;
 ```
 
 ## <a name="make_error_code"></a> make_error_code
@@ -64,7 +68,7 @@ error_condition make_error_condition(std::errc error) noexcept;
 ### Parameters
 
 *error*\
-The `std::errc` enumeration value to store in the error code object.
+The `std::errc` enumeration value to store in the error condition object.
 
 ### Return Value
 
@@ -74,7 +78,7 @@ The error condition object.
 
 ## <a name="system_category"></a> system_category
 
-Represents the category for errors caused by low-level system overflows.
+Represents the category for operating system errors.
 
 ```cpp
 const error_category& system_category() noexcept;