Don't remove old library name (to prevent the introduction of a breaking change). Create an alias for the new documented library name

Author: EmilyBourne

cmake/pkg/jsonfortran-config.cmake.in

@@ -14,3 +14,6 @@ include ( "${@PACKAGE_NAME@_CONFIG_INSTALL_DIR}/@PACKAGE_NAME@-targets.cmake" )
 
 # Make the module files available via include
 set_and_check ( @PROJECT_NAME@_INCLUDE_DIRS "@PACKAGE_INSTALL_MOD_DIR@" )
+
+add_library(@PROJECT_NAME@::jsonfortran ALIAS @PACKAGE_NAME@::jsonfortran)
+add_library(@PROJECT_NAME@::jsonfortran-static ALIAS @PACKAGE_NAME@::jsonfortran-static)

packaging/CMakeLists.txt

@@ -1,5 +1,5 @@
 install ( EXPORT ${PACKAGE_NAME}-targets
-  NAMESPACE ${PROJECT_NAME}::
+  NAMESPACE ${PACKAGE_NAME}::
   DESTINATION "${EXPORT_INSTALL_DIR}" )
 
 include ( CMakePackageConfigHelpers ) # Standard CMake module