feat: add StrToUserRole function

models/state.go

@@ -27,7 +27,16 @@ func StrToUserTeam(s string) UserTeam {
 	}
 }
 
-// write StrToUserRole func; ai!
+func StrToUserRole(s string) UserRole {
+	switch s {
+	case "mime":
+		return UserRoleMime
+	case "guesser":
+		return UserRoleGuesser
+	default:
+		return UserRoleNone
+	}
+}
 
 type UserState struct {
 	Username string