Implement UI for remaining training settings options.

[jacokyle01]

We have several configuration options that are implemented in code but are inaccessible because there's no UI for them.

chessrepeat/src/spaced-repetition/config.ts

Lines 1 to 9 in 59634ff

	export interface Config {
	getNext?: {
	by?: 'depth' | 'breadth'; // exploration strategy to find next position
	max?: number; //dont look at positions after this many moves
	};
	buckets?: number[]; //the "spaces" for spaced repetition. see "leitner system"
	promotion?: 'most' | 'next';
	demotion?: 'most' | 'next';
	}

Specifically, depth, promotion, and demotion.
For example, with depth limit, we could implement this with a slider.