By TOM SHANAHAN Pro Football Hall of Famers Bill Walsh of the San Francisco 49ers and Chuck Noll of the Pittsburgh Steelers receive the lion’s share of credit among NFL coaches for having provided Black coaching opportunities. And rightly so. The NFL, left on its own, moved at a glacial pace. It needed to be prodded. When Jimmy Raye was hired in 1977 by then-49ers head coach Ken Meyer, there were only seven other Black assistants in a…