add melpa install instructions

README.md

@@ -6,7 +6,9 @@ Flymake backend for Javascript using eslint
 ## Installation
 
 0. Make sure `eslint` is installed and present on your emacs `exec-path`.  For Linux systems `exec-path` usually equals your `$PATH` environment variable; for other systems, you're on your own.
-1. Download and place inside `~/.emacs.d/lisp`
+1. Install:
+  - from MELPA: `M-x package-install [RET] flymake-eslint [RET]`
+  - manually: download and place inside `~/.emacs.d/lisp`
 2. Edit `~/.emacs` or equivalent:
 ```lisp
 (add-to-list 'load-path "~/.emacs.d/lisp")