doc/requirements.rst: split media/optimisation libraries

diff --git a/doc/requirements.rst b/doc/requirements.rst
index 76d3d67..900292c 100644 (file)
--- a/doc/requirements.rst
+++ b/doc/requirements.rst
@@ -31,6 +31,9 @@ unusual location.
     If ``pkg-config`` is not found in ``PATH``, the configure step will
     succeed, but none of the external libraries will be used.
 
+Media libraries
+---------------
+
 libav
 .....
 
@@ -78,6 +81,9 @@ To enable this option, configure with ``--enable-samplerate``. The build will
 then fail if the required library is not found. To disable this option,
 configure with ``--disable-samplerate``
 
+Optimisation libraries
+----------------------
+
 libfftw3
 ........