Use by:
make -f dat/luahelper [target]
Target examples:
Visual Studio nmake : make -f dat/luahelper devhelp-nmake >file.txt
msys2 GNUmakefile : make -f dat/luahelper devhelp-msys >file.txt
Xcode project.pbxproj: make -f dat/luahelper devhelp-xcode >file.txt
all: generate txt files for all the above