more blurb about finder/query methods

hibernate-core/src/main/java/org/hibernate/annotations/processing/package-info.java

@@ -21,8 +21,31 @@
  * </ul>
  * <p>
  * Annotations in this package control Hibernate's compile-time
- * tooling. For example, this code defines a DAO-style repository
- * object:
+ * tooling, and depend on the use of the annotation processors
+ * in the {@code hibernate-jpamodelgen} or {@code query-validator}
+ * modules. If the appropriate annotation processor is not enabled
+ * at build time, these annotations have no effect.
+ * <p>
+ * Finder methods and query methods are usually declared by an
+ * interface, say {@code Queries}, and their implementations
+ * are generated into a class whose name follows the convention
+ * of the JPA static metamodel, that is, {@code Queries_}.
+ * <ul>
+ * <li>If the interface declares a method which returns an
+ *     {@code EntityManager}, Hibernate session, stateless
+ *     session, or reactive session, the generated class
+ *     implements the interface, {@code class Queries_ implements
+ *     Queries}, the generated methods are instance methods, and
+ *     the session must be provided to the class constructor,
+ *     possibly via dependency injection.
+ * <li>Otherwise, if there is no such method, the generated class
+ *     is non-instantiable, {@code abstract class Queries_}, the
+ *     generated methods are declared {@code static}, and the
+ *     session must be provided as an argument by the caller of
+ *     the generated methods.
+ * </ul>
+ * <p>
+ * For example, this code defines a DAO-style repository object:
  * <pre>
  * package org.example;
  *