Add hack library and fix links
Add hack library and fix links

cblanc/postcodes.io,ideal-postcodes/postcodes.io,ideal-postcodes/postcodes.io,cblanc/postcodes.io,goingdotin/postcodes.io,ideal-postcodes/postcodes.io,cblanc/postcodes.io,goingdotin/postcodes.io,goingdotin/postcodes.io