Merge pull request #58 from nncl/enhancement/update-angular

Angular 12+ Support

fix: Updating compilation errors

fix: Fixing compilation bug

fix: Adjusting strict mode rules

chore: Updating Angular version to 12

chore: Updating angular version to 12

1.9.1

From now on you can do the opposite of invalidDates, so only the dates

you pass through validDates' property will be enabled, all others are
disabled.

https://github.com/nncl/ngx-datepicker/issues/27

New options for disabling dates

- Disabling previous dates by today
- Disabling specific dates through a timestamp array