Documentation: Add ProjectExplorer plugin..

Reformat existing documentation to qdoc.

src/plugins/projectexplorer/customwizard/customwizardpreprocessor.cpp

@@ -188,7 +188,7 @@ bool PreprocessContext::process(const QString &in, QString *out, QString *errorM
             *errorMessage = msgEmptyStack(l);
             return false;
         }
-        QString expression;
+    QString expression;
         bool expressionValue = false;
         PreprocessStackEntry &top = m_sectionStack.back();
 
@@ -258,6 +258,26 @@ bool PreprocessContext::process(const QString &in, QString *out, QString *errorM
     return true;
 }
 
+/*!
+    \brief Custom wizard preprocessor based on JavaScript expressions.
+
+    Preprocess a string using simple syntax:
+    \code
+Text
+@if <JavaScript-expression>
+Bla...
+@elsif <JavaScript-expression2>
+Blup
+@endif
+\endcode
+
+    The JavaScript-expressions must evaluate to integers or boolean, like
+    \c '2 == 1 + 1', \c '"a" == "a"'. The variables of the custom wizard will be
+    expanded before, so , \c "%VAR%" should be used for strings and \c %VAR% for integers.
+
+    \sa ProjectExplorer::CustomWizard
+*/
+
 bool customWizardPreprocess(const QString &in, QString *out, QString *errorMessage)
 {
     PreprocessContext context;