Add completions for chef-shell, chef-solo, and chef-client

These were generated using the create_manpage_completions script on Chef 11.8.0's man pages. The default "See Man Page" truncation is replaced with "See --help" since there are many cases where the man pages either aren't installed or are not in the path.

This does *not* include completions for `knife` or any of its subcommands, which would be the most useful thing to have.

Running the script on these gives me:

```
Considering man1/knife.1
   Trying parser Deroffing man parser
   man1/knife.1 contains no options or is unparsable (tried parser Deroffing man parser)
```

for each of the subcommands. I've never deroffed a thing in my life so any help understanding why these fail would be great. The files it's using are here: https://github.com/opscode/chef/tree/11.8.0/distro/common/man/man1