mv comma initializer to page 1

doc/C01_TutorialMatrixClass.dox

@@ -16,6 +16,7 @@ This page is the first one in a much longer multi-page tutorial.
   - \ref TutorialMatrixDynamic
   - \ref TutorialMatrixConstructors
   - \ref TutorialMatrixCoeffAccessors
+  - \ref TutorialMatrixCommaInitializer
   - \ref TutorialMatrixSizesResizing
   - \ref TutorialMatrixAssignment
   - \ref TutorialMatrixFixedVsDynamic
@@ -144,6 +145,14 @@ The operator[] is also overloaded for index-based access in vectors, but keep in
 take more than one argument. We restrict operator[] to vectors, because an awkwardness in the C++ language
 would make matrix[i,j] compile to the same thing as matrix[j] !
 
+\section TutorialMatrixCommaInitializer Comma-initialization
+
+Matrix and vector coefficients can be conveniently set using the so-called \em comma-initializer syntax.
+For now, it is enough to know this example:
+\include Tutorial_commainit_01.cpp
+Output: \verbinclude Tutorial_commainit_01.out
+The right hand side can also contains matrix expressions as discussed in \ref TutorialAdvancedInitialization "this page".
+
 \section TutorialMatrixSizesResizing Resizing
 
 The current sizes can be retrieved by rows(), cols() and size(). Resizing a dynamic-size matrix is done by the resize() method.

doc/C02_TutorialMatrixArithmetic.dox

@@ -11,7 +11,6 @@ between matrices, vectors and scalars with Eigen.
 
 \b Table \b of \b contents
   - \ref TutorialArithmeticIntroduction
-  - \ref TutorialArithmeticMentionCommaInitializer
   - \ref TutorialArithmeticAddSub
   - \ref TutorialArithmeticScalarMulDiv
   - \ref TutorialArithmeticMentionXprTemplates
@@ -30,14 +29,6 @@ linear-algebraic operations. For example, \c matrix1 \c * \c matrix2 means matri
 and \c vector \c + \c scalar is just not allowed. If you want to perform all kinds of array operations,
 not linear algebra, see \ref TutorialArrayClass "next page".
 
-\section TutorialArithmeticMentionCommaInitializer A note about comma-initialization
-
-In examples below, we'll be initializing matrices with a very convenient device known as the \em comma-initializer.
-For now, it is enough to know this example:
-\include Tutorial_commainit_01.cpp
-Output: \verbinclude Tutorial_commainit_01.out
-The comma initializer is discussed in \ref TutorialAdvancedInitialization "this page".
-
 \section TutorialArithmeticAddSub Addition and substraction
 
 The left hand side and right hand side must, of course, have the same numbers of rows and of columns. They must