Support new `upload` field type

GitHub now have this new type:
https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/syntax-for-githubs-form-schema#upload

Using the parser I see this error:
```
Error: Unknown field type: upload
```

It would be good to provide support. Or at least omit it so it doesn't break.

從輸出「Unknown field type: upload」的parser進入點開始，將其支援的欄位類型與GitHub的upload schema文件進行比較。定義解析或省略upload欄位時的預期行為，接著確認現有欄位的解析仍然正常運作，且upload不再中斷處理。

由索引模型根據 Issue 內容生成。