Denishawn bibliography updated

I've updated the Denishawn bibliography. Citations were added - mostly from the New York Times and Washington Post - for a bunch of brief articles. Among the material added was a small article mentioning a previously unrecorded Denishawn performance in New York City. The performance (which was not part of their 1922-1923 tour) was a benefit, and took place in May, 1923. The article did not mention Louise Brooks by name, only that Ruth St. Denis, Ted Shawn and the Densiahwn dancers would be present.