Update README

Author: markslorach

README.md

@@ -11,7 +11,7 @@ A ful-stack application to view information on the countries of the world. Based
 * View a list of all countries
 * Search for a country
 * Filter countries by region
-* Sort countries ascending or descending order
+* Sort countries by ascending or descending order
 * View more info about a country and its bordering countries
 * Optional user authentication
 * Logged in users can add countries to favourites