Add typescript types to package exports

[jrouleau]

Fixes #191

[HalfdanJ]

I ran into the exact same issue, and this solved it perfectly.

[jobjen02]

Please merge this. We cannot deploy due to this issue!!

[alexciesielski]

necessary indeed

[jpzwarte]

Ran into the same thing.

[Regaddi]

I felt smart in attempting to fix this temporarily using patch-package, but apparently one can't easily patch a package's package.json as part of a patch.

⁉️  Not creating patch file for package 'tinykeys'
⁉️  There don't appear to be any changes.

So the only options are:

• Fork this package
• Copy the source (400 bytes, right? MIT License, right?)
• Get this PR merged and published in a new version

[heyitsarpit]

@jamiebuilds please merge this