minor #6785 Twig reference: Add links from routing functions to special routing parameters (alexislefebvre)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #6785).

Discussion
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Twig reference: Add links from routing functions to special routing parameters

The Twig reference doesn't explain what is the `parameters` parameter. I added a link to a section that explain the *Special Routing Parameters*.

Commits
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b1b30d9 Twig reference: Add links from path() and url() functions to "Linking"

Author: xabbuh

reference/twig_reference.rst

@@ -342,6 +342,10 @@ Returns the relative URL (without the scheme and host) for the given route.
 If ``relative`` is enabled, it'll create a path relative to the current
 path. More information in :ref:`templating-pages`.
 
+.. seealso::
+
+    Read :doc:`/routing` to learn more about the Routing component.
+
 url
 ~~~
 
@@ -360,6 +364,10 @@ Returns the absolute URL (with scheme and host) for the given route. If
 ``schemeRelative`` is enabled, it'll create a scheme-relative URL. More
 information in :ref:`templating-pages`.
 
+.. seealso::
+
+    Read :doc:`/routing` to learn more about the Routing component.
+
 absolute_url
 ~~~~~~~~~~~~