A group concerned with rapid development in Brooklyn has started to look at what park space is still available for residents to enjoy in a particular segment of the borough.Elected officials, local NYCHA residents, parks advocates, and neighborhood organizers took part in a walking tour last month from Fort Greene Park to the Brooklyn Navy Yard. The May 9 “Walk & Talk” tour, organized by New Yorkers for Parks (NY4P), was designed to look at the …