doc: minor documentation fixes after package infrastructure changes

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

docs/manual/adding-packages-autotools.txt

@@ -4,7 +4,7 @@ Infrastructure for autotools-based packages
 [[autotools-package-tutorial]]
 
 +autotools-package+ tutorial
-~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 First, let's see how to write a +.mk+ file for an autotools-based
 package, with an example :
@@ -64,7 +64,7 @@ package to be built.
 [[autotools-package-reference]]
 
 +autotools-package+ reference
-~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The main macro of the autotools package infrastructure is
 +autotools-package+. It is similar to the +generic-package+ macro. The ability to

docs/manual/adding-packages-cmake.txt

@@ -4,7 +4,7 @@ Infrastructure for CMake-based packages
 [[cmake-package-tutorial]]
 
 +cmake-package+ tutorial
-~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~
 
 First, let's see how to write a +.mk+ file for a CMake-based package,
 with an example :
@@ -63,7 +63,7 @@ package to be built.
 [[cmake-package-reference]]
 
 +cmake-package+ reference
-~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The main macro of the CMake package infrastructure is
 +cmake-package+. It is similar to the +generic-package+ macro. The ability to

docs/manual/adding-packages-generic.txt

@@ -9,7 +9,7 @@ system is based on hand-written Makefiles or shell scripts.
 [[generic-package-tutorial]]
 
 +generic-package+ Tutorial
-~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ------------------------------
 01: #############################################################
@@ -90,7 +90,7 @@ Makefile code necessary to make your package working.
 [[generic-package-reference]]
 
 +generic-package+ Reference
-~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 There are two variants of the generic target. The +generic-package+ macro is
 used for packages to be cross-compiled for the target.  The