Update package.json typings field

[diesal11]

'typings' in package.json needs to point to the Declaration file. It currently points to the just the folder

As a result IDEs like VSCode will auto import from 'canvas/typings' instead of canvas, This will fix that issue

• Have you updated CHANGELOG.md?

[zbjornson]

Are you using Typescript 3.5.1 by chance? It looks like microsoft/TypeScript@5d188a8#diff-0049ad7158cd6170295446b6b60cb8a7 perhaps inadvertently changed the behavior; "index.d.ts" used to be implied. I'm good with this change (being explicit is good) but if the above is true, then I'm sure lots of packages will break once 3.5.1 becomes mainstream.

[zbjornson]

Hm, no. I can't reproduce the issue you described with typescript 3.5.1 either.

[diesal11]

Nope, my VSCode & project are currently on TS version 3.4.5. This may have been an error specific to VSC? I just noticed the incorrect imports and this seemed to fix the problem :)