[phpcs] Add documentation

phpcs.xml

@@ -3,27 +3,46 @@
   <description>Created with the PHP Coding Standard Generator. http://edorian.github.com/php-coding-standard-generator/</description>
   <exclude-pattern>./css</exclude-pattern>
   <exclude-pattern>./vendor</exclude-pattern>
+  <!-- Duplicate class names are not allowed -->
   <rule ref="Generic.Classes.DuplicateClassName"/>
+  <!-- Statements must not be empty -->
   <rule ref="Generic.CodeAnalysis.EmptyStatement"/>
+  <!-- Unconditional if-statements are not allowed -->
   <rule ref="Generic.CodeAnalysis.UnconditionalIfStatement"/>
+  <!-- Do not use final statements inside final classes -->
   <rule ref="Generic.CodeAnalysis.UnnecessaryFinalModifier"/>
+  <!-- Do not override methods to call their parent -->
   <rule ref="Generic.CodeAnalysis.UselessOverridingMethod"/>
+  <!-- One line should not have more than 80 characters -->
+  <!-- One line must never exceed 120 characters -->
   <rule ref="Generic.Files.LineLength">
     <properties>
       <property name="lineLimit" value="80"/>
       <property name="absoluteLineLimit" value="120"/>
     </properties>
   </rule>
+  <!-- Use UPPERCARE for constants -->
   <rule ref="Generic.NamingConventions.UpperCaseConstantName"/>
+  <!-- Use lowercase for 'true', 'false' and 'null' -->
   <rule ref="Generic.PHP.LowerCaseConstant"/>
+  <!-- Use a single string instead of concating -->
   <rule ref="Generic.Strings.UnnecessaryStringConcat"/>
+  <!-- Use tabs for indentation -->
   <rule ref="Generic.WhiteSpace.DisallowSpaceIndent"/>
+  <!-- Parameters with default values must appear last in functions -->
   <rule ref="PEAR.Functions.ValidDefaultValue"/>
+  <!-- Use PascalCase for class names -->
   <rule ref="PEAR.NamingConventions.ValidClassName"/>
+  <!-- Use 'elseif' instead of 'else if' -->
   <rule ref="PSR2.ControlStructures.ElseIfDeclaration"/>
+  <!-- Add a new line at the end of a file -->
   <rule ref="PSR2.Files.EndFileNewline"/>
+  <!-- Do not add spaces when casting -->
   <rule ref="Squiz.WhiteSpace.CastSpacing"/>
+  <!-- Operators must have a space around them -->
   <rule ref="Squiz.WhiteSpace.OperatorSpacing"/>
+  <!-- Do not add a whitespace before a semicolon -->
   <rule ref="Squiz.WhiteSpace.SemicolonSpacing"/>
+  <!-- Do not add whitespace at start or end of a file or end of a line -->
   <rule ref="Squiz.WhiteSpace.SuperfluousWhitespace"/>
 </ruleset>