Clarify sizes of 11-digit code areas (#256)
Clarify sizes of 11-digit code areas (#256)

Fixing issue #254
bocops/open-location-code,bocops/open-location-code,google/open-location-code,zongweil/open-location-code,google/open-location-code,bocops/open-location-code,zongweil/open-location-code,zongweil/open-location-code,google/open-location-code,google/open-location-code,zongweil/open-location-code,zongweil/open-location-code,google/open-location-code,bocops/open-location-code,google/open-location-code,bocops/open-location-code,bocops/open-location-code,zongweil/open-location-code,zongweil/open-location-code,bocops/open-location-code,google/open-location-code,zongweil/open-location-code,google/open-location-code,zongweil/open-location-code,google/open-location-code,bocops/open-location-code,google/open-location-code,zongweil/open-location-code,bocops/open-location-code,bocops/open-location-code,zongweil/open-location-code,google/open-location-code,bocops/open-location-code