Updated the installation of components introduced in Symfony 3.4

Author: javiereguiluz

components/cache.rst

@@ -19,10 +19,13 @@ The Cache Component
 Installation
 ------------
 
-You can install the component in 2 different ways:
+.. code-block:: terminal
 
-* :doc:`Install it via Composer </components/using_components>` (``symfony/cache`` on `Packagist`_);
-* Use the official Git repository (https://github.com/symfony/cache).
+    $ composer require symfony/cache
+
+Alternatively, you can clone the `<https://github.com/symfony/cache>`_ repository.
+
+.. include:: /components/require_autoload.rst.inc
 
 Cache (PSR-6) Versus Simple Cache (PSR-16)
 ------------------------------------------

components/dotenv.rst

@@ -14,10 +14,11 @@ The Dotenv Component
 Installation
 ------------
 
-You can install the component in 2 different ways:
+.. code-block:: terminal
+
+    $ composer require symfony/dotenv
 
-* :doc:`Install it via Composer </components/using_components>` (``symfony/dotenv`` on `Packagist`_);
-* Use the official Git repository (https://github.com/symfony/dotenv).
+Alternatively, you can clone the `<https://github.com/symfony/dotenv>`_ repository.
 
 .. include:: /components/require_autoload.rst.inc
 

components/lock.rst

@@ -14,10 +14,11 @@ The Lock Component
 Installation
 ------------
 
-You can install the component in 2 different ways:
+.. code-block:: terminal
 
-* :doc:`Install it via Composer </components/using_components>` (``symfony/lock`` on `Packagist`_);
-* Use the official Git repository (https://github.com/symfony/lock).
+    $ composer require symfony/lock
+
+Alternatively, you can clone the `<https://github.com/symfony/lock>`_ repository.
 
 .. include:: /components/require_autoload.rst.inc
 

components/workflow.rst

@@ -14,10 +14,11 @@ The Workflow Component
 Installation
 ------------
 
-You can install the component in 2 different ways:
+.. code-block:: terminal
 
-* :doc:`Install it via Composer </components/using_components>` (``symfony/workflow`` on `Packagist`_);
-* Use the official Git repository (https://github.com/symfony/workflow).
+    $ composer require symfony/workflow
+
+Alternatively, you can clone the `<https://github.com/symfony/workflow>`_ repository.
 
 .. include:: /components/require_autoload.rst.inc