doc/user: building - promote dependencies to a higher-level section

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

doc/user/building.rst

@@ -159,9 +159,9 @@ This issue is tracked in https://github.com/mesonbuild/meson/issues/1967.
 
 .. _building_dependencies:
 
-..............................................................................
+------------------------------------------------------------------------------
 Build dependencies
-..............................................................................
+------------------------------------------------------------------------------
 
 libinput has a few build-time dependencies that must be installed prior to
 running meson.