Add typescript support

[bruceborrett]

Description

Currently there is no support for Typescript. Modules cannot be written using Typescript and using the package in a Typescript project causes many Typescript errors.

Proposed solution

Create definition files declaring the various functions and their return values. Also, add support for modules to be written in Typescript.

[StorytellerCZ]

I'm wondering if this could be fixed by adding the typescript package to the bundler and watcher. Thoughts?

[a4xrbj1]

Where does this request rank vs upgrading ElectronJS now that Meteor version 3.x is out?

Every month we’re falling further and further behind, Snyk keeps flagging severe risk and is asking me to upgrade to much higher versions.

Any thoughts on this @StorytellerCZ ?

[StorytellerCZ]

Secondary to upgrade. I hope that this will be simple enough by adding typescript package to the bundler and watcher. Looks like I just need to figure out the proper version.