Typos fixed

Misspelled alphanumeric and alphabetic.

README.md

@@ -63,8 +63,8 @@ $(document).ready(function(){
 #### Default masking definitions
 
   - 9 : numeric
-  - a : alfabetic
-  - * : alfanumeric 
+  - a : alphabetic
+  - * : alphanumeric 
 
 There are more definitions defined within the extensions.  
 You can find info within the js-files or by further exploring the options.