Enhancement: `enabled-dates` attribute

[dextermb]

Hey,

I would like to see the enabled-dates attribute added to this component to make it easier to disable a large number of dates. I current only want to enable Saturdays, or a select few Saturdays.

With the current functionality of the component I would have to generate a reasonable amount of dates to pass into disabled-dates which doesn't seem to be efficient.

If, for whatever reason, adding enabled-dates is out of scope I would like there to be an EventEmitter when changing year/month, this way I can generate a months worth of disabled dates at a time.

Current behavior

• I must build an array of disabled dates for a reasonable timespan around the current date.

Expected/desired behavior

• I would like to pass an array of enabled dates, and then the component would handle disabling all other dates.

Other information

• I noticed that this had already been mentioned ([enable-dates] functionality  #196) but nothing happened after the initial mention of it.