Added documentation about the Vertere CSV2RDF Mapping language

.gitignore

@@ -25,3 +25,5 @@ Examples/panini_stickers/upload/*
 Examples/panini_stickers/output_data/*
 
 Examples/adventureWorks/output_data/adventureworks.rdf.ttl
+
+.DS_Store

custom/conversions.class.php

@@ -0,0 +1,23 @@
+<?php
+/*
+ * Class for custom conversion methods
+ */
+class Conversions {
+    /*
+     * Converts a value from feet to metres
+     */
+	public static function feet_to_metres($value) {
+		return ($value * 0.3048);
+	}
+
+	public static function metres_to_feet($value) {
+		return ($value * 3.2808);
+	}
+
+    /*
+     * Example pass-through function
+     */
+    public static function mirror($value) {
+		return $value;
+	}
+}