Merge pull request #254 from php-http/bundle-cache-plugin-optional

mention that cache-plugin is not required in httplug bundle

Author: dbu

integrations/symfony-bundle.rst

@@ -279,6 +279,11 @@ service names follow the pattern ``httplug.plugin.<name>``:
                 plugins:
                     - 'httplug.plugin.cache'
 
+.. note::
+
+    To configure HTTP caching, you need to require ``php-http/cache-plugin`` in
+    your project. It is available as a separate composer package.
+
 To use a custom plugin or when you need specific configuration that is not
 covered by the bundle configuration, you can configure the plugin as a normal
 symfony service and then reference that service name in the plugin list of your

integrations/symfony-full-configuration.rst

@@ -40,7 +40,7 @@ This page shows an example of all configuration values provided by the bundle.
                 my_service:
                     type: 'service'
                     service: 'my_authentication_service'
-            cache:
+            cache: # requires the php-http/cache-plugin package to be installed in your package
                 cache_pool: 'my_cache_pool'
                 stream_factory: 'httplug.stream_factory'
                 config: