Add documentation for haxe.Json functions.

std/haxe/Json.hx

@@ -24,14 +24,29 @@ package haxe;
 /**
 	Crossplatform JSON API : it will automatically use the optimized native API if available.
 	Use -D haxeJSON to force usage of the Haxe implementation even if a native API is found : this will provide
-	extra encoding features such as enums (replaced by their index), Hashs and Iterable.
+	extra encoding features such as enums (replaced by their index) and StringMaps.
 **/
 class Json {
 
+	/**
+		Parses given JSON-encoded `text` and returns the resulting object.
+
+		JSON objects are parsed into anonymous structures and JSON arrays
+		are parsed into Array<Dynamic>.
+
+		If given `text` is not valid JSON, an exception will be thrown.
+	**/
 	public static inline function parse( text : String ) : Dynamic {
 		return haxe.format.JsonParser.parse(text);
 	}
 
+	/**
+		Encodes given `value` and returns the resulting JSON string.
+
+		If `replacer` is given and is not null, it is used to retrieve
+		actual object to be encoded. The `replacer` function two parameters,
+		the key and the value being encoded. Initial key value is an empty string.
+	**/
 	public static inline function stringify( value : Dynamic, ?replacer:Dynamic -> Dynamic -> Dynamic ) : String {
 		return haxe.format.JsonPrinter.print(value, replacer);
 	}