minor #11038 Some docs fixes (OskarStark)

This PR was squashed before being merged into the 3.4 branch (closes #11038).

Discussion
----------

Some docs fixes

Please review commit by commit

Commits
-------

0b751ed Some docs fixes

Author: javiereguiluz

console/commands_as_services.rst

@@ -122,7 +122,7 @@ Or set the ``command`` attribute on the ``console.command`` tag in your service
 
         use AppBundle\Command\SunshineCommand;
 
-        //...
+        // ...
 
         $container
             ->register(SunshineCommand::class)

contributing/code/standards.rst

@@ -29,9 +29,7 @@ Symfony Coding Standards in Detail
 If you want to learn about the Symfony coding standards in detail, here's a
 short example containing most features described below:
 
-.. code-block:: html+php
-
-    <?php
+.. code-block:: php
 
     /*
      * This file is part of the Symfony package.

doctrine/repository.rst

@@ -25,7 +25,7 @@ To do this, add the repository class name to your entity's mapping definition:
          */
         class Product
         {
-            //...
+            // ...
         }
 
     .. code-block:: yaml

page_creation.rst

@@ -45,7 +45,6 @@ random) number and prints it. To do that, create a "Controller class" and a
 "controller" method inside of it that will be executed when someone goes to
 ``/lucky/number``::
 
-    <?php
     // src/AppBundle/Controller/LuckyController.php
     namespace AppBundle\Controller;
 

service_container/service_subscribers_locators.rst

@@ -356,10 +356,10 @@ will share identical locators amongst all the services referencing them::
 
     public function process(ContainerBuilder $container)
     {
-        //...
+        // ...
 
         $locateableServices = [
-            //...
+            // ...
             'logger' => new Reference('logger'),
         ];