Help: Add code example for INSTALL_INTERFACE to cmake-buildsystem.
Help: Link to cmake-buildsystem from CMP0052 docs.
Merge topic 'CMP0052-docs' into next

692228e4 Help: Link to cmake-buildsystem from CMP0052 docs.
e5e9b8e9 Help: Add code example for INSTALL_INTERFACE to cmake-buildsystem.