fix: typecheck failures and running pnpm i under Volta

[skyfeiz]

• <- Keep this line and put an x between the brackts.

Description

Linked Issues

fix typecheck error in [#22]

fix error in running pnpm i under Volta

$ pnpm i

Volta error: Could not locate executable `pnpm` in your project.

Please ensure that all project dependencies are installed with `npm install` or `yarn install`