man/checkers/variableScope.md: rewrite description and motivation

man/checkers/variableScope.md

@@ -1,19 +1,23 @@
 # variableScope
 
 **Message**: The scope of the variable 'x' can be reduced.<br/>
-**Category**: Code Quality<br/>
+**Category**: Readability<br/>
 **Severity**: Style<br/>
 **Language**: C/C++
 
 ## Description
 
-A variable is declared in an outer scope than where it's actually used - narrowing its declaration to
-the innermost block that needs it makes the code easier to follow.
+A variable is declared in an outer scope, it can be declared in an inner scope.
 
 ## Motivation
 
-A variable declared too early forces a reader to track its lifetime across code that doesn't use it,
-and makes it unclear at a glance which block actually depends on it.
+It is common practice, especially in C++ code, to declare variables in inner scope when
+possible.
+
+The motivation is to make the code more readable.
+
+Opinions about what is more readable can differ so make your own decisions - these warnings
+can be easily suppressed.
 
 ## How to fix