Update development mode default caching docs (rails#52474)

* Update development mode  default caching docs

* code review fix

Co-authored-by: Rafael Mendonça França <[email protected]>

Author: nikhilbhatt

guides/source/caching_with_rails.md

@@ -34,7 +34,7 @@ fragment caching. By default Rails provides fragment caching. In order to use
 page and action caching you will need to add `actionpack-page_caching` and
 `actionpack-action_caching` to your `Gemfile`.
 
-By default, caching is only enabled in your production environment. You can play
+By default, action controller caching is only enabled in your production environment. You can play
 around with caching locally by running `rails dev:cache`, or by setting
 [`config.action_controller.perform_caching`][] to `true` in `config/environments/development.rb`.
 
@@ -720,10 +720,11 @@ response.strong_etag = response.body # => "618bbc92e2d35ea1945008b42799b0e7"
 
 Caching in Development
 ----------------------
+By default, caching is *enabled* in development mode with
+[`:memory_store`](#activesupport-cache-memorystore).
 
-It's common to want to test the caching strategy of your application
-in development mode. Rails provides the rails command `dev:cache` to
-easily toggle caching on/off.
+Rails also provides the rails command `dev:cache` to
+easily toggle action controller caching on/off.
 
 ```bash
 $ bin/rails dev:cache
@@ -732,8 +733,7 @@ $ bin/rails dev:cache
 Development mode is no longer being cached.
 ```
 
-By default, when development mode caching is *off*, Rails uses
-[`:null_store`](#activesupport-cache-nullstore).
+To disable caching set `cache_store` to [`:null_store`](#activesupport-cache-nullstore)
 
 References
 ----------

railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt

@@ -17,8 +17,8 @@ Rails.application.configure do
   # Enable server timing.
   config.server_timing = true
 
-  # Enable/disable caching. By default caching is disabled.
-  # Run rails dev:cache to toggle caching.
+  # Enable/disable action controller caching. By default action controller caching is disabled.
+  # Run rails dev:cache to toggle action controller caching.
   if Rails.root.join("tmp/caching-dev.txt").exist?
     <%- unless options.api? -%>
     config.action_controller.perform_caching = true