feat: add typings for toast custom props

[maciekgrzybek]

Information

First of all, thanks for this great library :) I'm currently implementing it in our system, and I notice I have a need to pass custom props in the toast method, so I can use them when rendering toasts. This already seems to be working, but types aren't covering this situation so I added them in this PR. What do you think?

[vercel[bot]]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/timo/react-hot-toast/6L6R6CbmCkSLJqPX9ZqY3ofct2Hj
✅ Preview: https://react-hot-toast-git-fork-maciekgrzybek-feat-add-ty-56e9c1-timo1.vercel.app

[maciekgrzybek]

Hey @timolins any chance you could take a look at this? :)