Add typescript support

[aeharding]

Hello!

Thanks for considering this PR. 🙂

Some things of note:

1. Prettier on my editor formats code in the readme. Let me know, and I can revert + add to .pretterignore if this is not wanted.
2. I had to remove standard.js, as its not compatible with typescript. I just used the react default. lmk and I can change this to something else! (ts-standard?)
3. withServiceWorkerUpdater was hard to type (there's a couple as) but the API for the end user is nice :)

I've tested the example/ folder, along with a separate app (via npm link). Hopefully nothing seems too off.

And if you'd like, feel free to push changes directly to my branch.

[aeharding]

Not sure if there's a specific type this should be associated with.

[emibcn]

• message: This can be any structured-clonable type
• structured-clonable type

It looks pretty unknown (any type of simple or complex data, but not functions or classes). I'm not TypeScript expert and maybe exists something specific for this.

[emibcn]

Hi @aeharding !!
Great job!! I have done several tests (apart from the CI ones, on side projects) and it continues working well, so I approved and merged this PR.

I'm about to publish a new version of the NPM package, but I'm in doubt about the version number to assign. Do you think this is a minor change (1.1.0) or it deserves considering it as a major one (2.0.0)?

Thanks for your contributions!!

[aeharding]

Thank you!! Hmm, good question. I guess strictly looking at semantic versioning it would be a minor version change, since it's fully backwards compatible without breaking changes to Javascript projects.

But 2.0.0 might be more clear to typescript users that 1.x isn't compatible (in case a TS user downloads 2.0.0 but wants to try an older version for whatever reason.)

Either way seems fine by me :)

[emibcn]

Published with major version change ;)