doc: minor cleanup.

doc/features.dox

@@ -27,13 +27,13 @@ namespace Magnum {
 /** @page features Feature overview
 @brief Fundamental principles and design goals.
 
-- @subpage platform -- @copybrief platform
-- @subpage types -- @copybrief types
-- @subpage matrix-vector -- @copybrief matrix-vector
-- @subpage transformations -- @copybrief transformations
-- @subpage plugins -- @copybrief plugins
-- @subpage scenegraph -- @copybrief scenegraph
-- @subpage shapes -- @copybrief shapes
-- @subpage debug-tools -- @copybrief debug-tools
+-   @subpage platform -- @copybrief platform
+-   @subpage types -- @copybrief types
+-   @subpage matrix-vector -- @copybrief matrix-vector
+-   @subpage transformations -- @copybrief transformations
+-   @subpage plugins -- @copybrief plugins
+-   @subpage scenegraph -- @copybrief scenegraph
+-   @subpage shapes -- @copybrief shapes
+-   @subpage debug-tools -- @copybrief debug-tools
 */
 }