formatted brew completion

clean_files.txt

@@ -57,6 +57,7 @@ plugins/available/xterm.plugin.bash
 
 # completions
 #
+completion/available/brew.completion.bash
 completion/available/cargo.completion.bash
 completion/available/knife.completion.bash
 completion/available/packer.completion.bash

completion/available/brew.completion.bash

@@ -1,4 +1,6 @@
-#!/usr/bin/env bash
+# shellcheck shell=bash
+cite "about-completion"
+about-completion "brew completion"
 
 # Load late to make sure `system` completion loads first
 # BASH_IT_LOAD_PRIORITY: 375