doc: keywords to make important pages more accessible.

doc/building.dox

@@ -28,6 +28,8 @@ namespace Magnum {
 /** @page building Downloading and building
 @brief Guide how to download and build Magnum on different platforms.
 
+@m_keywords{Building}
+
 @tableofcontents
 @m_footernavigation
 

doc/cmake.dox

@@ -27,6 +27,8 @@ namespace Magnum {
 /** @page cmake Usage with CMake
 @brief Guide how to find and use Magnum with CMake build system
 
+@m_keywords{CMake}
+
 @tableofcontents
 @m_footernavigation
 

doc/opengl-mapping.dox

@@ -28,6 +28,8 @@ namespace Magnum {
 /** @page opengl-mapping Command mapping
 @brief List of OpenGL commands corresponding to particular Magnum API.
 
+@m_keyword{OpenGL command mapping,,}
+
 @tableofcontents
 @m_footernavigation
 

doc/opengl-support.dox

@@ -26,6 +26,8 @@
 /** @page opengl-support Support state
 @brief List of (un)supported OpenGL features and extensions.
 
+@m_keyword{OpenGL support state,,}
+
 @tableofcontents
 @m_footernavigation
 

doc/opengl-workarounds.dox

@@ -27,6 +27,8 @@ namespace Magnum {
 /** @page opengl-workarounds Driver workarounds
 @brief List of OpenGL driver workarounds used by Magnum
 
+@m_keyword{OpenGL driver workarounds,,}
+
 @m_footernavigation
 
 Driver workarounds used by a particular app are listed in the engine startup