Fix typo "unobtrusive" instead of "unobstrusive"

Author: FagnerMartinsBrack

README.md

@@ -97,7 +97,7 @@ Cookies2.set('name', 'value');
 
 ## JSON
 
-js-cookie provides unobstrusive JSON storage for cookies.
+js-cookie provides unobtrusive JSON storage for cookies.
 
 When creating a cookie you can pass an Array or Object Literal instead of a string in the value. If you do so, js-cookie will store the string representation of the object according to `JSON.stringify`: