Visibly link to the base interface docs from all plugin classes.

So people new to the plugin stuff can quickly get to usage introduction
and code snippets. The plugins alone don't list anything like that and
it may be *very* confusing otherwise.

src/MagnumPlugins/AnyAudioImporter/AnyImporter.h

@@ -72,6 +72,13 @@ Only loading from files is supported.
 
 @section Audio-AnyImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Audio library and is built if
 `MAGNUM_WITH_ANYAUDIOIMPORTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnyAudioImporter" @ce via

src/MagnumPlugins/AnyImageConverter/AnyImageConverter.h

@@ -84,6 +84,13 @@ is supported.
 
 @section Trade-AnyImageConverter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    via the base @ref AbstractImageConverter interface. See its documentation
+    for introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_ANYIMAGECONVERTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnyImageConverter" @ce via

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h

@@ -111,6 +111,13 @@ formats that are marked as such in the list above.
 
 @section Trade-AnyImageImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_ANYIMAGEIMPORTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnyImageImporter" @ce via

src/MagnumPlugins/AnySceneConverter/AnySceneConverter.h

@@ -69,6 +69,13 @@ Only converting to files is supported.
 
 @section Trade-AnySceneConverter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractSceneConverter interface. See its
+    documentation for introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_ANYSCENECONVERTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnySceneConverter" @ce via

src/MagnumPlugins/AnySceneImporter/AnySceneImporter.h

@@ -102,6 +102,13 @@ format, however @ref ImporterFeature::FileCallback is supported as well.
 
 @section Trade-AnySceneImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_ANYSCENEIMPORTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnySceneImporter" @ce via

src/MagnumPlugins/AnyShaderConverter/AnyConverter.h

@@ -94,6 +94,13 @@ explicitly set.
 
 @section ShaderTools-AnyConverter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractConverter interface. See its documentation
+    for introduction and usage examples.
+
 This plugin depends on the @ref ShaderTools library and is built if
 `MAGNUM_WITH_ANYSHADERCONVERTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "AnyShaderConverter" @ce via

src/MagnumPlugins/MagnumFont/MagnumFont.h

@@ -118,6 +118,13 @@ rectangle=45 0 44 25
 
 @section Text-MagnumFont-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractFont interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Text library and the
 @ref Trade::TgaImporter "TgaImporter" plugin. It is built if
 `MAGNUM_WITH_MAGNUMFONT` is enabled when building Magnum. To use as a dynamic

src/MagnumPlugins/MagnumFontConverter/MagnumFontConverter.h

@@ -60,6 +60,13 @@ passed @ref AbstractGlyphCache to support @ref GlyphCacheFeature::ImageDownload.
 
 @section Text-MagnumFontConverter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractFontConverter interface. See its
+    documentation for introduction and usage examples.
+
 This plugin depends on the @ref Text library and the
 @ref Trade::TgaImageConverter "TgaImageConverter" plugin. It is built if
 `MAGNUM_WITH_MAGNUMFONTCONVERTER` is enabled when building Magnum. To use as a

src/MagnumPlugins/ObjImporter/ObjImporter.h

@@ -62,6 +62,13 @@ Loads Wavefront OBJ (`*.obj`) files, with the following supported features:
 
 @section Trade-ObjImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_OBJIMPORTER` is enabled when building Magnum. To use as a dynamic
 plugin, load @cpp "ObjImporter" @ce via @ref Corrade::PluginManager::Manager.

src/MagnumPlugins/TgaImageConverter/TgaImageConverter.h

@@ -60,6 +60,13 @@ Creates Truevision TGA (`*.tga`) files from images with format
 
 @section Trade-TgaImageConverter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    via the base @ref AbstractImageConverter interface. See its documentation
+    for introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_TGAIMAGECONVERTER` is enabled when building Magnum. To use as a
 dynamic plugin, load @cpp "TgaImageConverter" @ce via

src/MagnumPlugins/TgaImporter/TgaImporter.h

@@ -62,6 +62,13 @@ grayscale images with 8 bits per channel.
 
 @section Trade-TgaImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin depends on the @ref Trade library and is built if
 `MAGNUM_WITH_TGAIMPORTER` is enabled when building Magnum. To use as a dynamic
 plugin, load @cpp "TgaImporter" @ce via @ref Corrade::PluginManager::Manager.

src/MagnumPlugins/WavAudioImporter/WavImporter.h

@@ -78,6 +78,13 @@ a `RIFX` header) are supported, data is converted to machine endian on import.
 
 @section Audio-WavImporter-usage Usage
 
+@m_class{m-note m-success}
+
+@par
+    This class is a plugin that's meant to be dynamically loaded and used
+    through the base @ref AbstractImporter interface. See its documentation for
+    introduction and usage examples.
+
 This plugin is built if `MAGNUM_WITH_WAVAUDIOIMPORTER` is enabled when building
 Magnum. To use dynamic plugin, load @cpp "WavAudioImporter" @ce
 via @ref Corrade::PluginManager::Manager.