Merge pull request #7 from Conduitry/patch-1

mention additional arguments in readme

README.md

@@ -16,13 +16,13 @@ npm i estree-walker
 var walk = require( 'estree-walker' ).walk;
 var acorn = require( 'acorn' );
 
-ast = acorn.parse( sourceCode, options ); // https://github.com/marijnh/acorn
+ast = acorn.parse( sourceCode, options ); // https://github.com/acornjs/acorn
 
 walk( ast, {
-  enter: function ( node, parent ) {
+  enter: function ( node, parent, prop, index ) {
     // some code happens
   },
-  leave: function ( node, parent ) {
+  leave: function ( node, parent, prop, index ) {
   	// some code happens
   }
 });
@@ -42,4 +42,4 @@ None of which should be taken as criticism of estraverse, which has more feature
 
 ## License
 
-MIT
+MIT