Update README.md

README.md

 # Deduped map tilelist
 
-Given an input file with a list of line seperated tiles in `{zoom}/{x}/{y}` format, generate a distinct list of map tiles for all zoom levels up to `maxzoom`.
+Given an input file with a list of line seperated tiles in `{zoom}/{x}/{y}` format, generate a distinct list of map tiles for all zoom levels from `minzoom` up to `maxzoom`.
 
 ## Usage