Added more links to screencast videos

Author: javiereguiluz

frontend.rst

@@ -1,6 +1,11 @@
 Managing CSS and JavaScript
 ===========================
 
+.. admonition:: Screencast
+    :class: screencast
+
+    Do you prefer video tutorials? Check out the `Webpack Encore screencast series`_.
+
 Symfony ships with a pure-JavaScript library - called Webpack Encore - that makes
 working with CSS and JavaScript a joy. You can use it, use something else, or just
 create static CSS and JS files in your ``public/`` directory and include them in your
@@ -101,3 +106,4 @@ Other Front-End Articles
 .. _`Mix`: https://laravel.com/docs/5.4/mix
 .. _`Symfony`: http://symfony.com/
 .. _`Full API`: https://github.com/symfony/webpack-encore/blob/master/index.js
+.. _`Webpack Encore screencast series`: https://knpuniversity.com/screencast/webpack-encore

security.rst

@@ -4,6 +4,11 @@
 Security
 ========
 
+.. admonition:: Screencast
+    :class: screencast
+
+    Do you prefer video tutorials? Check out the `Symfony Security screencast series`_.
+
 Symfony's security system is incredibly powerful, but it can also be confusing
 to set up. In this article you'll learn how to set up your application's security
 step-by-step, from configuring your firewall and how you load users, to denying
@@ -1341,3 +1346,4 @@ Other Security Related Topics
 .. _`frameworkextrabundle documentation`: https://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/index.html
 .. _`HWIOAuthBundle`: https://github.com/hwi/HWIOAuthBundle
 .. _`Symfony ACL bundle`: https://github.com/symfony/acl-bundle
+.. _`Symfony Security screencast series`: https://knpuniversity.com/screencast/symfony3-security

service_container.rst

@@ -5,6 +5,11 @@
 Service Container
 =================
 
+.. admonition:: Screencast
+    :class: screencast
+
+    Do you prefer video tutorials? Check out the `Symfony Fundamentals screencast series`_.
+
 Your application is *full* of useful objects: a "Mailer" object might help you
 send emails while another object might help you save things to the database.
 Almost *everything* that your app "does" is actually done by one of these objects.
@@ -1063,3 +1068,4 @@ Learn more
 .. _`service-oriented architecture`: https://en.wikipedia.org/wiki/Service-oriented_architecture
 .. _`Symfony Standard Edition (version 3.3) services.yaml`: https://github.com/symfony/symfony-standard/blob/3.3/app/config/services.yml
 .. _`glob pattern`: https://en.wikipedia.org/wiki/Glob_(programming)
+.. _`Symfony Fundamentals screencast series`: https://knpuniversity.com/screencast/symfony3-fundamentals