cache support (#607) (#608)

docs/src/main/asciidoc/spring-cloud-openfeign.adoc

@@ -122,6 +122,7 @@ Spring Cloud OpenFeign provides the following beans by default for feign (`BeanT
 * `Encoder` feignEncoder: `SpringEncoder`
 * `Logger` feignLogger: `Slf4jLogger`
 * `MicrometerCapability` micrometerCapability: If `feign-micrometer` is on the classpath and `MeterRegistry` is available
+* `CachingCapability` cachingCapability: If `@EnableCaching` annotation is used. Can be disabled via `feign.cache.enabled`.
 * `Contract` feignContract: `SpringMvcContract`
 * `Feign.Builder` feignBuilder: `FeignCircuitBreaker.Builder`
 * `Client` feignClient: If Spring Cloud LoadBalancer is on the classpath, `FeignBlockingLoadBalancerClient` is used.
@@ -141,7 +142,7 @@ Spring Cloud OpenFeign _does not_ provide the following beans by default for fei
 * `Collection<RequestInterceptor>`
 * `SetterFactory`
 * `QueryMapEncoder`
-* `Capability` (`MicrometerCapability` is provided by default)
+* `Capability` (`MicrometerCapability` and `CachingCapability` are provided by default)
 
 A bean of `Retryer.NEVER_RETRY` with the type `Retryer` is created by default, which will disable retrying.
 Notice this retrying behavior is different from the Feign default one, where it will automatically retry IOExceptions,
@@ -602,6 +603,22 @@ public class FooConfiguration {
 }
 ----
 
+=== Feign Caching
+
+If `@EnableCaching` annotation is used, a `CachingCapability` bean is created and registered so that your Feign client recognizes `@Cache*` annotations on its interface:
+
+[source,java,indent=0]
+----
+public interface DemoClient {
+
+	@GetMapping("/demo/{filterParam}")
+    @Cacheable(cacheNames = "demo-cache", key = "#keyParam")
+	String demoEndpoint(String keyParam, @PathVariable String filterParam);
+}
+----
+
+You can also disable the feature via property `feign.cache.enabled=false`.
+
 === Feign @QueryMap support
 
 The OpenFeign `@QueryMap` annotation provides support for POJOs to be used as