isSameYear(date: BikramSambat): boolean
Returns true if the provided Bikram Sambat date has the same year as the current date.
const date1 = new BikramSambat('2078-05-15')
const date2 = new BikramSambat('2077-05-15')
const isSameYear = date1.isSameYear(date2) // false