Create a jsoncppConfig.cmake file, even if building under meson

jsoncppConfig.cmake.meson.in

@@ -0,0 +1,6 @@
+@PACKAGE_INIT@
+
+add_library(jsoncpp_lib IMPORTED SHARED)
+set_target_properties(jsoncpp_lib PROPERTIES
+  IMPORTED_LOCATION "${PACKAGE_PREFIX_DIR}/lib/libjsoncpp.so"
+  INTERFACE_INCLUDE_DIRECTORIES "${PACKAGE_PREFIX_DIR}/include")

meson.build

@@ -62,6 +62,13 @@ import('pkgconfig').generate(
   filebase : 'jsoncpp',
   description : 'A C++ library for interacting with JSON')
 
+cmakeconf = configuration_data()
+
+import('cmake').configure_package_config_file(
+  name: 'jsoncpp',
+  input: 'jsoncppConfig.cmake.meson.in',
+  configuration: cmakeconf)
+
 # for libraries bundling jsoncpp
 jsoncpp_dep = declare_dependency(
   include_directories : jsoncpp_include_directories,