Feature Request for DARK MODE

[Saqib92]

Ionic version: (check one with "x")
[ ] 2.x
[ ] 3.x
[ x] 4.x
[ x] 5.x

Ion2-calendar mode: (check one with "x")
[ x] components mode
[ ] modal mode

I'm submitting a ... (check one with "x")
[ ] bug report
[ x] feature request
[ ] help me

Current behavior:

Expected behavior:

There Should be a DarkMode option in options to enable Dark mode.
Steps to reproduce:

Related code:

 optionsRange: CalendarComponentOptions = {
    darkMode: true // default false to update background color + disable dates color and other colors
  };

Other information:

Ionic info: (run ionic info from a terminal/cmd prompt and paste output below):

`Ionic:

   Ionic CLI : 6.12.3

Utility:

   cordova-res (update available: 0.15.2) : 0.15.1
   native-run (update available: 1.3.0)   : 1.0.0

System:

   NodeJS : v12.18.3
   npm    : 6.14.6
   OS     : Windows 10`