Link between configuration.md and cache_store documentation [ci skip]

Co-authored-by: Jonathan Hefner <[email protected]>

guides/source/configuring.md

@@ -71,7 +71,7 @@ These configuration methods are to be called on a `Rails::Railtie` object, such
 * `config.beginning_of_week` sets the default beginning of week for the
 application. Accepts a valid day of week as a symbol (e.g. `:monday`).
 
-* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, `:redis_cache_store`, or an object that implements the cache API. Defaults to `:file_store`.
+* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, `:redis_cache_store`, or an object that implements the cache API. Defaults to `:file_store`. See [Cache Stores](caching_with_rails.html#cache-stores) for per-store configuration options.
 
 * `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to `true`.