Added standard bundle installation instructions

cookbook/bundles/best_practices.rst

@@ -268,6 +268,53 @@ semantic configuration described in the cookbook.
     If you are defining services, they should also be prefixed with the bundle
     alias.
 
+Installation instructions
+-------------------------
+
+In order to ease the installation process of third-party bundles, we propose
+you to use the following standardized instructions in your ``README`` file:
+
+.. code-block::
+
+    Installation
+    ============
+
+    Step 1: Download the bundle
+    ---------------------------
+
+    Use Composer to add the bundle as a new dependency of your project:
+
+    .. code-block:: bash
+
+        $ composer require "<vendor>/<bundle-name>:dev-master"
+
+    This command requires to have installed Composer globally, as explained
+    `in the installation chapter <https://getcomposer.org/doc/00-intro.md>`_
+    of Composer documentation.
+
+    Step 2: Enable the bundle
+    -------------------------
+
+    Then, enable the bundle adding the following line in the ``AppKernel`` class
+    of your project:
+
+    .. code-block:: php
+
+        <?php
+        // app/AppKernel.php
+
+        public function registerBundles()
+        {
+            $bundles = array(
+                // ...
+
+                new <vendor>\<bundle-name>\<bundle-long-name>(),
+            );
+        }
+
+    (optionally add *Step 3*, *Step 4*, etc. to explain other required
+    installation steps, such as registering routes or dumping assets)
+
 Learn more from the Cookbook
 ----------------------------