Set GENERATE_TAGFILE in Doxyfile
Set GENERATE_TAGFILE in Doxyfile

Allows documentation to be linked from other projects to https://nlohmann.github.io/json using Doxygen with the tag:
TAGFILES = $(SOME_PATH)/nlohmann_json.tag=https://nlohmann.github.io/json
nlohmann/json,kaidokert/json,theodelrieu/json,kaidokert/json,nlohmann/json,theodelrieu/json,nlohmann/json,kaidokert/json