Improve readability of the documentation

Added emphasis as per PR review and added additional standards so that the documentation is easier to read (split by logic as suggested in the PR review).

Author: dingo-d

src/Standards/PSR12/Docs/ControlStructures/ControlStructureSpacingStandard.xml

@@ -1,7 +1,7 @@
 <documentation title="Control Structure Spacing">
     <standard>
     <![CDATA[
-    Control structures MUST have correct spacing.
+    The control structures must have one space after the control structure keyword, no spaces after the opening parenthesis and before the closing parenthesis, and one space between the closing parenthesis and the opening brace.
     ]]>
     </standard>
     <code_comparison>
@@ -32,46 +32,56 @@ if ($expr<em> </em>) {
         ]]>
         </code>
     </code_comparison>
+    <standard>
+    <![CDATA[
+    The body of the multi-line control structure must be indented once, placing the body on the next line after the opening brace.
+    ]]>
+    </standard>
     <code_comparison>
-        <code title="Valid: Each line in a multi-line control structure condition block indented at least once. Default indentation is 4 spaces.">
+        <code title="Valid: First expression of a multi-line control structure condition block is on the line after the opening parenthesis.">
         <![CDATA[
 while (
-<em>    </em>$expr1
-<em>    </em>&& $expr2
+    <em>$expr1</em>
+    && $expr2
 ) {
 }
         ]]>
         </code>
-        <code title="Invalid: Some lines in a multi-line control structure condition block not indented correctly.">
+        <code title="Invalid: First expression of a multi-line control structure condition block is on the same line as the opening parenthesis.">
         <![CDATA[
-while (
-<em></em>$expr1
+while (<em></em>$expr1
     && $expr2
-<em>  </em>&& $expr3
 ) {
 }
         ]]>
         </code>
     </code_comparison>
     <code_comparison>
-        <code title="Valid: First expression of a multi-line control structure condition block is on the line after the opening parenthesis.">
+        <code title="Valid: Each line in a multi-line control structure condition block indented at least once. Default indentation is 4 spaces.">
         <![CDATA[
 while (
-    $expr1
-    && $expr2
+<em>    </em>$expr1
+<em>    </em>&& $expr2
 ) {
 }
         ]]>
         </code>
-        <code title="Invalid: First expression of a multi-line control structure condition block is on the same line as the opening parenthesis.">
+        <code title="Invalid: Some lines in a multi-line control structure condition block not indented correctly.">
         <![CDATA[
-while (<em></em>$expr1
+while (
+<em></em>$expr1
     && $expr2
+<em>  </em>&& $expr3
 ) {
 }
         ]]>
         </code>
     </code_comparison>
+    <standard>
+    <![CDATA[
+    The closing parenthesis of the multi-line control structure must be on the next line after the body, indented to the same level as the start of the control structure.
+    ]]>
+    </standard>
     <code_comparison>
         <code title="Valid: The closing parenthesis of a multi-line control structure condition block is on the line after the last expression.">
         <![CDATA[
@@ -97,7 +107,7 @@ while (
 while (
     $expr1
     && $expr2
-) {
+<em>)</em> {
 }
         ]]>
         </code>