Allow more than 12 months in calendar

[Cavva79]

Hi @Paul-DS,
as you asked me to open a new issue for this feature in #32 I open this issue copying from my comment #32 (comment)

I'm trying to show a period of time from 11 nov 2020 to 10 nov 2021. Obviusly it is an year but spans on 13 months.
I think this

js-year-calendar/src/ts/js-year-calendar.ts

Line 235 in 5e0e89f

numberMonthsDisplayed: !isNaN(parseInt(opt.numberMonthsDisplayed)) && opt.numberMonthsDisplayed > 0 && opt.numberMonthsDisplayed <= 12 ? parseInt(opt.numberMonthsDisplayed) : 12,

could be easy switched to

numberMonthsDisplayed: !isNaN(parseInt(opt.numberMonthsDisplayed)) 
     && opt.numberMonthsDisplayed > 0 ? parseInt(opt.numberMonthsDisplayed) : 12,

to allow more than 12 months or try to implement intermediate startDate.

[fhfournier]

numberMonthsDisplayed: 13 still not working on version 2.0.0