Fix doxygen section bugs

docs/x11/install.md

@@ -16,7 +16,7 @@ IMPORTANT NOTE:
   example: wxX11 2.8.0, gcc 2.95.4, Redhat 6.2
 
 First steps                            {#x11_first_steps}
------------
+===========
 
 - Download wxX11-x.y.z.tgz, where x.y.z is the version number.
   Download documentation in a preferred format, such as

interface/wx/listctrl.h

@@ -151,7 +151,7 @@ enum
     2.8 was removed in wxWidgets 3.1, meaning for wxWidgets 3.1+ wxOSX uses the generic
     implementation for all modes.
 
-    @subsection column_order Column Ordering
+    @section column_order Column Ordering
 
     By default, the columns of a list control appear on the screen in order
     of their indices, i.e. column 0 appears first, then column 1 next,

interface/wx/webview.h

@@ -309,7 +309,7 @@ public:
     WebKit on macOS and GTK. This allows the correct viewing of complex pages with
     JavaScript and CSS.
 
-    @section descriptions Backend Descriptions
+    @section backend_descriptions Backend Descriptions
 
     This class supports using multiple backends, corresponding to different
     implementations of the same functionality. Under macOS and Unix platforms