Abstract class generated as regular class

[mustofa-id]

abstract classes are emitted as regular classes in the generated .d.ts file. this removes the abstract modifier and causes incorrect typings.

example:

abstract class Base {
	protected abstract readonly type: Type;

	protected async getConfig(): Promise<Config> {
		return { /* ... */ };
	}
}

generated .d.ts:

class Base {
	protected abstract readonly type: Type;
	protected getConfig(): Promise<Config>
}

version: >= v0.6.0