docs: drop code references to local plan files

tests/Service/Assignment/AssignmentPlannerTest.php

@@ -13,7 +13,7 @@ use App\Service\Assignment\AssignmentPlanner;
 use PHPUnit\Framework\TestCase;
 
 /**
- * One test per row of the planner table in .ddev/plans/teamer-auto-assignments-plan.md.
+ * Pins the rules listed on AssignmentPlanner, one test per case.
  */
 class AssignmentPlannerTest extends TestCase
 {