minor #6801 [Doc] Clarify that AdminDashboard only works for pretty URLs (javiereguiluz)

This PR was merged into the 4.x branch.

Discussion
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[Doc] Clarify that AdminDashboard only works for pretty URLs

Fixes #6782.

Commits
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d704291 [Doc] Clarify that AdminDashboard only works for pretty URLs

Author: javiereguiluz

doc/dashboards.rst

@@ -175,6 +175,11 @@ Legacy Admin URLs
     If you are using :ref:`pretty admin URLs <pretty-admin-urls>` in your application,
     you can skip this section entirely.
 
+.. caution::
+
+    Legacy admin URLs are deprecated and will no longer work in EasyAdmin 5.0.
+    Upgrade your application to use :ref:`pretty URLs <pretty-admin-urls>`.
+
 Before the introduction of :ref:`pretty admin URLs <pretty-admin-urls>`, EasyAdmin
 used a single Symfony route to serve all dashboard URLs. The needed information
 is passed using query string parameters. If you generated the dashboard with the
@@ -230,6 +235,12 @@ or PHP attributes (if the project requires PHP 8 or newer).
             // ...
         }
 
+.. caution::
+
+    In backends that don't use :ref:`pretty URLs <pretty-admin-urls>`, the ``Route``
+    annotation/attribute is the only recommended way to configure the dashboard route.
+    The ``#[AdminDashboard]`` attribute doesn't work with traditional (ugly) URLs.
+
 .. note::
 
     Since ``index()`` is part of the Dashboard interface, you cannot add arguments