dev package doesn't include *Config.cmake files

[nega]

For several years now, Ogg has supported auto-generated and exported CMake configuration, especially when building Ogg with CMake. Properly installed, this allows someone to merely use `find_package(Ogg)` in their CMake project without having to jump through hoops. An example where this is done well in Ubuntu is qtbase5-dev.

$ dpkg -L qtbase5-dev |grep Config.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5/Qt5Config.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Concurrent/Qt5ConcurrentConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Core/Qt5CoreConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5DBus/Qt5DBusConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5EglFsKmsSupport/Qt5EglFsKmsSupportConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Gui/Qt5GuiConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Network/Qt5NetworkConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5OpenGLExtensions/Qt5OpenGLExtensionsConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5PrintSupport/Qt5PrintSupportConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Sql/Qt5SqlConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Test/Qt5TestConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5Xml/Qt5XmlConfig.cmake

An example where this is done well for Ogg is Homebrew @ https://github.com/Homebrew/homebrew-core/blob/175a655dbe76d08350ff941f9c9d7fd9ef2933d0/Formula/lib/libogg.rb

Please include the `*Config.cmake` files (and friends) in the Ogg family of packages.