fix typos

docs/adr/adr-013-inferring-la-from-postcode.md

@@ -5,8 +5,8 @@ The Office for National Statistics (ONS) publishes the National Statistics
 Postcode Lookup (NSPL) and ONS Postcode Directory (ONSPD) datasets, 
 which may be used to find a local authority district for a postcode when compiling statistics. 
 
-We're using postcodesio API with postcodesio gem.
-Postcodesio uses OS and ONS data which is updated as soon as new data becomes available.
+We're using postcodes.io API with postcodes_io gem.
+Postcodes.io uses OS and ONS data which is updated as soon as new data becomes available.
 
 We are not using OS places API due to the lack of data. 
 Closest datapoint to LA in OS places api is ADMINISTRATIVE_AREA which does not always match with local authority.