It's gonna be a scorcher today, the first day of Williamsburg Walks -- where the neighborhood creates a pedestrian-only zone on Bedford Avenue between Metropolitan and North 9th Street. Metro reports on a local artist who will be on hand that may be feeling the heat a little bit more than others. Yvette Helin dresses in all black, depicting the walk symbols one might see on a traffic sign; today she'll be a pedestrian crossing......