A simple Makefile 'help' command (dwmkerr.com)

While I'm not a big fan of separate build systems not built into the language, Make seems like the only real standard we have that can be used to gather a set of commands in one obvious place that everyone knows to look for(Unless someone knows a better way to implement an "index page" for a directory!).

Adding a "make help" command seems like a really nice one line addition to any cli project.