After short introduction in #32 we decided to extend this package with independence_year Property:

• independence_year Property is a Number of year when country became independent
• For countries that have no year available it should be set to 0, null or year when country was settled (TBD)

After adding new property, each Country {Object} should contain:

{
  "country": "poland",
  "capital": "warsaw",
  "currency": "zloty",
  "native_language": ["polish"],
  "famous_for": "pierogi and potatoes",
  "phone_code": "+48",
  "flag": "https://flagpedia.net/data/flags/h80/pl.png",
  "drive_direction": "right",
  // NEW DATA
  "independence_year": 1918
},

Additionally there will be new method to use that data:

• getCountriesByIndependenceYear(independenceYear)
• getCountriesByIndependenceYearRange(fromYear, toYear)