Merge branch '3.4' into 4.4

* 3.4:
  Encore: add documentation for Encore.configureDevServerOptions()

Author: javiereguiluz

frontend/encore/dev-server.rst

@@ -17,14 +17,35 @@ Twig shortcuts (or are :ref:`processing your assets through entrypoints.json <lo
 in some other way), you're done: the paths in your templates will automatically point
 to the dev server.
 
-You can also pass options to the ``dev-server`` command: any options that are supported
-by the normal `webpack-dev-server`_. For example:
+The ``dev-server`` command supports all the options defined by `webpack-dev-server`_.
+You can set these options via command line options:
 
 .. code-block:: terminal
 
     $ yarn encore dev-server --https --port 9000
 
-This will start a server at ``https://localhost:9000``.
+You can also set these options using the ``Encore.configureDevServerOptions()``
+method in your ``webpack.config.js`` file:
+
+.. code-block:: javascript
+
+    // webpack.config.js
+    // ...
+
+    Encore
+        // ...
+
+        .configureDevServerOptions(options => {
+            options.https = {
+                key: '/path/to/server.key',
+                cert: '/path/to/server.crt',
+            }
+        })
+    ;
+
+.. versionadded:: 0.28.4
+
+    The ``Encore.configureDevServerOptions()`` method was introduced in Encore 0.28.4.
 
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