zsh code completion doesn't work

After following these instructions:

```
$ curl https://cheat.sh/:zsh > ~/.zsh.d/_cht
$ echo 'fpath=(~/.zsh.d/ $fpath)' >> ~/.zshrc
$ # Open a new shell to load the plugin
```

zsh completion doesn't work.

iTerm2 latest @ macOS 10.15.5

Reproduce the commands using the :zsh endpoint, ~/.zsh.d/_cht, and ~/.zshrc on the reported macOS and iTerm2 setup. Check whether zsh loads the completion file and identify what prevents completion; done means the documented setup provides working zsh completion.

Written by the indexing model from the issue text.