shouldn't --completion for zsh also complete paths?

Hi,

I was struggling to make `-- --completion` work with both my arguments and paths. For example I have a "--path" argument and I would like to autocomplete files paths instead of treating it as a flag.

The workaround I found was to do `sed 's/compgen -W/compgen -f -W/g'`

Is there something I'm missing or should I make a PR to add this '-f' by default?

首先定位 Python Fire 的 `--completion` 輸出實作，並檢查它如何產生 zsh 或 shell 補全指令。重現 `--path` 範例，將產生的輸出與 `compgen -f -W` 這個替代方案進行比較，並確認路徑補全能正常運作而不會破壞 flag 補全。

由索引模型根據 Issue 內容生成。