#2 numeric type (#8)

* Update informations
* Make errors parameter in result constructor optional
* Add new section in readme
* Add implementation and specification for numeric type

Author: Christian Blank

README.md

@@ -54,4 +54,23 @@ $result = Checker::fulfills($data, $requirement);
 ```
 The returned object holds information about the analysis. You can
 check the result by calling `isValid()` on the result object. To
-fetch the errors, simply call `getErrors`.
+fetch the errors, simply call `getErrors`.
+
+## Supported Types
+
+Currently the following types are supported:
+
+ * Any
+ * Nullable
+ * Bool
+ * Numeric
+ * Float
+ * Int
+ * String
+ * Object
+ * List
+ 
+There are some open issues with ideas for more types. Feel free to send pull requests.
+
+Additionally you can implement the `TypeInterface` and use your own type implementations.
+