Add script to update auto-completed commands
user
```ruby
#!/usr/bin/env ruby

# Use this script to update the commands auto-completed in plugin/packer.vim.

require 'open3'

command_re = /^\s\s\s\s(\w+)/
plugin_file = 'plugin/packer.vim'

# Create the list of commands.
stdout, stderr, _status = Open3.capture3('packer list-commands')
output = if stderr == ''
           stdout.split("\n")
         else
           stderr.split("\n")
         end
commands = output.collect do |l|
  match = command_re.match(l)
  "  \\ \"#{match[1]}\"" if match
end.reject(&:nil?).join(",\n")

# Read in the existing plugin file.
plugin = File.open(plugin_file, 'r').readlines

# Replace the terraResourceTypeBI lines with our new list.
first = plugin.index { |l| /^  return join\(\[/.match(l) } + 1
last = plugin.index { |l| /^  \\ \], "\\n"\)/.match(l) }
plugin.slice!(first, last - first)
commands.split("\n").reverse_each do |r|
  plugin.insert(first, r)
end

# Write the plugin file back out.
File.open(plugin_file, 'w') do |f|
  f.puts plugin
end
```
assistant