Clean up README

plugins/supervisor/README.md

 # supervisor plugin
 
-This plugin adds tab-completion for supervisord/supervisorctl in [Supervisor](http://supervisord.org/).
-
-Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems.
+This plugin adds tab-completion for `supervisord`/`supervisorctl` in [Supervisor](http://supervisord.org/).
+Supervisor is a client/server system that allows its users to monitor and control a number
+of processes on UNIX-like operating systems.
 
 To use it, add `supervisor` to the plugins array in your zshrc file:
-
 ```zsh
 plugins=(... supervisor)
 ```