Update readme on how to load JSON with attributes.

README.mkdn

@@ -55,13 +55,18 @@ Springy 1.1+ supports simplified API for adding nodes and edges, see
         ['mark', 'other']
     );
 
-Springy 1.2+ also accepts JSON, see
+Springy 1.2+ also accepts JSON with node attributes, see
 [demo-json.html](http://dhotson.github.com/springy/demo-json.html):
 
     graphJSON = {
-      "nodes": ["mark", "higgs", "other", "etc"],
+      "nodes": [
+        ["mark", {"label":"Mark", "color":"#0000ff"}],
+        "higgs",
+        "other",
+        "etc"
+      ],
       "edges": [
-        ["mark", "higgs"],
+        ["mark", "higgs", {"label":"Foo", "color":"#ff0000"}],
         ["mark", "etc"],
         ["mark", "other"]
       ]

springy.js

@@ -90,12 +90,19 @@
 		// accepts variable number of arguments, where each argument
 		// is a string that becomes both node identifier and label
 		for (var i = 0; i < arguments.length; i++) {
-			var name = arguments[i];
-			var node = new Node(name, {label:name});
+			var arg = arguments[i];
+			var node;
+			if (typeof arg === "string") {
+				node = new Node(arg, {label:arg});
+			} else {
+				node = new Node(arg[0], arg[1]);
+			}
+
 			this.addNode(node);
 		}
 	};
 
+
 	Graph.prototype.addEdge = function(edge) {
 		var exists = false;
 		this.edges.forEach(function(e) {
@@ -168,14 +175,15 @@
 
 		{
 			"nodes": [
-				"center",
+				["center", {"label":"Center","color":"#ff0000"}],
 				"left",
 				"right",
 				"up",
 				"satellite"
 			],
 			"edges": [
-				["center", "left"],
+				["center", "left", {"label":"Foo"},"color":"#0000ff"],
+
 				["center", "right"],
 				["center", "up"]
 			]
@@ -193,7 +201,6 @@
 		}
 	}
 
-
 	// find the edges from node1 to node2
 	Graph.prototype.getEdges = function(node1, node2) {
 		if (node1.id in this.adjacency