leaderboard: createAdSize()

in src/lib/ad-sizes.ts [130:139]

• 9 lines of code
• 1 McCabe index (conditional complexity)

	leaderboard: createAdSize(728, 90),
	mobilesticky: createAdSize(320, 50),
	mpu: createAdSize(300, 250),
	portrait: createAdSize(300, 1050),
	skyscraper: createAdSize(160, 600),
	cascade: createAdSize(940, 230),
	portraitInterstitial: createAdSize(320, 480),
};

const standardAdSizes = {