phing: fix copy-paste error in README

plugins/phing/README.md

@@ -3,6 +3,7 @@
 This plugin adds autocompletion for [`phing`](https://github.com/phingofficial/phing) targets.
 
 To use it, add `phing` to the plugins array of your `.zshrc` file:
-```
-plugins=(... eecms)
+
+```zsh
+plugins=(... phing)
 ```