Add a help target to Makefile

[jubuyer]

Utilize GNU Make documentation to create a help target

Requirements

• Update make file with a command that lists what commands can be done
  • e.g. use @echo to list the targets and what they do
• List all the commands/target within main
  • Default make, clean, and help

Resources to see examples of targets and Make documentation can be found here.

Make sure to test within your terminal to see that the code compiles and works correctly!