Update README.md to add init documentation

[C-Loftus]

• For new users of lisp, it is unclear how quicklisp loads dependencies
  • I personally missed this the first time and I think others have too https://github.com/nobody-famous/alive/issues/197
• the quicklisp quickstart is fine but a bit verbose due to all the console output; it is easy for a new user who is skimming to miss how to auto load dependencies

Feel free to close or edit if you don't think this is reasonable.