function defaultLoaders() {
	return {
		name: 'default-loaders',
		async transform(code, id) {
			if (!/\.([tj]sx?|mjs)$/.test(id)) return;

			return await transformImports(code, id, {
				resolveId(specifier) {
					if (!hasCustomPrefix(specifier) && IMPLICIT_URL.test(specifier)) {
						return `url:${specifier}`;
					}
					return null;
				}
			});
		}
	};
}
Add default loaders to import specifiers if none are
present already.
@returns {import("wmr").Plugin}