Specify ID for cache providers section in reference docs

Closes gh-13551

Author: wilkinsona

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -4122,6 +4122,8 @@ NOTE: If you are using the cache infrastructure with beans that are not interfac
 make sure to enable the `proxyTargetClass` attribute of `@EnableCaching`.
 
 
+
+[[boot-features-caching-provider]]
 === Supported cache providers
 The cache abstraction does not provide an actual store and relies on abstraction
 materialized by the `org.springframework.cache.Cache` and