Link to installation instructions

Author: Nyholm

contributing/code/pull_requests.rst

@@ -420,11 +420,11 @@ type errors. The Psalm errors are not always correct, but each should be reviewe
 and discussed. A Pull Request should not update the psalm baseline nor add ``@psalm-``
 annotations.
 
-Psalm can run locally with:
+After the `Psalm phar is installed`_, the analysis can be run locally with:
 
 .. code-block:: terminal
 
-    $ psalm src/Symfony/Component/Workflow
+    $ psalm.phar src/Symfony/Component/Workflow
 
 .. _rework-your-patch:
 
@@ -463,3 +463,4 @@ before merging.
 .. _`searching on GitHub`: https://github.com/symfony/symfony/issues?q=+is%3Aopen+
 .. _`Symfony Slack`: https://symfony.com/slack-invite
 .. _`Travis-CI`: https://travis-ci.org/symfony/symfony
+.. _`Psalm phar is installed`: https://psalm.dev/docs/running_psalm/installation/