Add runs() and builds() top level endpoints

[mnmkng]

They're commented out and not implmented, but we already have both of them.

https://docs.apify.com/api/v2#/reference/actor-builds/build-collection/get-user-builds-list
https://docs.apify.com/api/v2#/reference/actor-runs/run-collection/get-user-runs-list

apify-client-js/src/apify_client.ts

Lines 109 to 115 in 80008ea

	// TODO we don't have this endpoint yet
	// /**
	// * @return {BuildCollectionClient}
	// */
	// builds() {
	// return new BuildCollectionClient(this._options());
	// }