Add the ability to explore organizations (#3573)

* Add ability to explore organizations

* Use right icon for org explore links

cmd/web.go

@@ -214,6 +214,7 @@ func runWeb(ctx *cli.Context) error {
 		})
 		m.Get("/repos", routers.ExploreRepos)
 		m.Get("/users", routers.ExploreUsers)
+		m.Get("/organizations", routers.ExploreOrganizations)
 	}, ignSignIn)
 	m.Combo("/install", routers.InstallInit).Get(routers.Install).
 		Post(bindIgnErr(auth.InstallForm{}), routers.InstallPost)