Improve threshold for promoting bundles to all.js

[DrewML]

bundlegento/src/computeBundles.ts

Lines 63 to 69 in f686c3d

	// TODO: Either make this threshold configurable,
	// or use a heuristic, something like (total bundles - 2)
	if (groups.size > 2) {
	// Move to the global shared file
	finalGroups.get('all')!.modules.add(dep);
	}
	}