Added standard bundle installation instructions

cookbook/bundles/best_practices.rst

@@ -194,6 +194,59 @@ Extensive documentation should also be provided in the
 the ``Resources/doc/`` directory; the ``Resources/doc/index.rst`` file is
 the only mandatory file and must be the entry point for the documentation.
 
+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.
+
+.. sidebar:: Installation Instructions Template
+
+    This template assumes that your bundle is in its ``1.x`` version. If not,
+    change the ``"~1"`` installation version accordingly (e.g. ``"~2"``).
+
+    .. raw:: md
+
+        Installation
+        ============
+
+        Step 1: Download the Bundle
+        ---------------------------
+
+        Use Composer to add the bundle as a new dependency of your project:
+
+        ```
+        $ composer require <package-name> "~1"
+        ```
+
+        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:
+
+        ```php
+        <?php
+        // app/AppKernel.php
+
+        public function registerBundles()
+        {
+            $bundles = array(
+                // ...
+
+                new <vendor>\<bundle-name>\<bundle-long-name>(),
+            );
+        }
+        ```
+
+    Optionally you can add *Step 3*, *Step 4*, etc. to explain other required
+    installation steps, such as registering routes or dumping assets.
+
+
 Routing
 -------