Hey, you want an athlete, go sign a dunk contest winner. So the Knicks did. Troy Williams, a listed 6-foot-7 small forward recently released by the Rockets, officially signed his 10-day contract with the Knicks on Wednesday and practiced with the team in Tarrytown. Among the items on Williams’ résumé is the 2017 D-League Dunk Contest championship. “Great fit, great opportunity, great coaches, great team, great players, everything. I like it a lot. I’m really excited,” said Williams, claiming he can supply “athleticism, another person that can run the court, hustle, defend, all that.” Williams, who averaged 5.6 points and 2.1 rebounds in 34 career games with the Rockets and Grizzlies over the past two seasons, caught the interest of several teams when Houston waived him to make room for Joe Johnson. “Their interest level here was a little bit higher than everybody else’s,” Williams said of the Knicks.