Add nlohmann_json

Author: Hind-M

CMakeLists.txt

@@ -474,7 +474,7 @@ include(CMakePackageConfigHelpers)
 set(SPARROW_EXPORTED_TARGETS sparrow)
 
 if(CREATE_JSON_READER_TARGET)
-    list(APPEND SPARROW_EXPORTED_TARGETS json_reader)
+    list(APPEND SPARROW_EXPORTED_TARGETS json_reader nlohmann_json)
 endif()
 
 install(TARGETS ${SPARROW_EXPORTED_TARGETS}