Directive theme input should also accept object

[Plutoz01]

Hi everyone,

Based on latest documentation, a given chart can be initialized with not just a predefined theme name but also can accept a given theme object as well.

I'd suggest to modify Directive's theme input type signiture to:

import { ThemeOption } from 'echarts/types/src/util/types';
// ...
export class NgxEchartsDirective implements OnChanges, OnDestroy, OnInit, AfterViewInit {
// ...
  @Input() theme: string | ThemeOption;
// ...
}

[xieziyu]

Thanks. It's supported in v7

[Plutoz01]

Thanks for the fix!