minor #12003 Small fixes (OskarStark)

This PR was squashed before being merged into the 4.2 branch (closes #12003).

Discussion
----------

Small fixes

Commits
-------

ed131d2 Small fixes

Author: OskarStark

cache.rst

@@ -278,7 +278,7 @@ Each custom pool becomes a service where the service id is the name of the pool
 using the camel case version of its name - e.g. ``custom_thing.cache`` can be
 injected automatically by naming the argument ``$customThingCache`` and type-hinting it
 with either :class:`Symfony\\Contracts\\Cache\\CacheInterface` or
-``Psr\\Cache\\CacheItemPoolInterface``::
+``Psr\Cache\CacheItemPoolInterface``::
 
     use Symfony\Contracts\Cache\CacheInterface;
 

components/cache/cache_pools.rst

@@ -27,7 +27,7 @@ Creating Cache Pools
 
 Cache Pools are created through the **cache adapters**, which are classes that
 implement both :class:`Symfony\\Contracts\\Cache\\CacheInterface` and
-``Psr\\Cache\\CacheItemPoolInterface``. This component provides several adapters
+``Psr\Cache\CacheItemPoolInterface``. This component provides several adapters
 ready to use in your applications.
 
 .. toctree::

form/create_custom_field_type.rst

@@ -401,7 +401,7 @@ The last step is to create the actual Twig template that will render the type.
 The template contents depend on which HTML, CSS and JavaScript frameworks and
 libraries are used in your application:
 
-.. code-block:: twig
+.. code-block:: html+twig
 
     {# templates/form/custom_types.html.twig #}
     {% block postal_address_row %}
@@ -485,7 +485,7 @@ for this form class and :doc:`tag it </service_container/tags>` with ``form.type
 The variables added in ``buildView()`` are available in the form type template
 as any other regular Twig variable:
 
-.. code-block:: twig
+.. code-block:: html+twig
 
     {# templates/form/custom_types.html.twig #}
     {% block postal_address_row %}

setup.rst

@@ -35,7 +35,7 @@ commands to create the Symfony application:
 
 The only difference between these two commands is the number of packages
 installed. The ``--full`` option installs all the packages that you usually
-need to build web apps. Therefore, the installation size will be much bigger.
+need to build web applications. Therefore, the installation size will be much bigger.
 
 Both commands will create a new ``my-project/`` directory, download some
 dependencies into it and even generate the basic directories and files you'll