Add documentation for @Cache and @nocache

Follows up on #17644

docs/src/main/asciidoc/resteasy-reactive.adoc

@@ -656,6 +656,15 @@ public class Endpoint {
 }
 ----
 
+=== Controlling HTTP Caching features
+
+RESTEasy Reactive provides the `@org.jboss.resteasy.reactive.Cache` and `@org.jboss.resteasy.reactive.NoCache` to facilitate hangling HTTP caching semantics, i.e. setting the 'Cache-Control' HTTP header.
+
+These annotations can be placed either on a Resource Method or a Resource Class (in which case it applies to all Resource Methods of the class that do *not* contain the same annotation) and allow users
+to return domain objects and not have to deal with building up the `Cache-Control` HTTP header explicitly.
+
+While `@Cache` builds a complex `Cache-Control` header, `@NoCache` is a simplified notation to say that you don't want anything cached; i.e. `Cache-Control: nocache`.
+
 === Accessing context objects
 
 [[context-objects]]

independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/Cache.java

@@ -5,6 +5,9 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Allows setting the {@code Cache-Control} header automatically.
+ */
 @Target({ ElementType.TYPE, ElementType.METHOD })
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Cache {

independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/NoCache.java

@@ -5,6 +5,9 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Allows setting the @{code Cache-Control} response header of "nocache"
+ */
 @Target({ ElementType.TYPE, ElementType.METHOD })
 @Retention(RetentionPolicy.RUNTIME)
 public @interface NoCache {