Save game data on a user's device

[silentDjay]

localstorage could be leveraged to make the gameplay more engaging.

Some ideas:

• keep track of the user's 'streak' of countries found with 3 or fewer (?) clicks
• do a 'campaign mode' where the user needs to find all countries (in a specified order)

[silentDjay]

campaign mode was just released with https://github.com/silentDjay/Mapstery/commit/c510ccfde78e3457bfd80c9987cfb82379ab8f40