feat(symfony-cli): introduce symfony-cli plugin

plugins/symfony-cli/README.md

@@ -0,0 +1,9 @@
+# Symfony CLI plugin
+
+This plugin adds completion for [Symfony CLI](https://symfony.com/download), the developer tool to help you build, run, and manage your Symfony applications directly from your terminal.
+
+To use it, add `symfony-cli` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... symfony-cli)
+```