Increase selectable range to 20 months in calendar

public/typo3conf/ext/ep_theme/Resources/Private/Assets/js/components/Calendar.vue

@@ -73,7 +73,7 @@
                 const months = [];
                 let month = this.startDate.month();
                 let year = this.startDate.year();
-                for (let i = 1; i <= 12; i++) {
+                for (let i = 1; i <= 20; i++) {
                     months.push(dayjs().set('year', year).set('month', month));
                     if (month < 12) {
                         month++;