support deno

[uriva]

the previous issue was closed #1798

this lib does work with npm: prefix, but not natively in deno

this causes a problem with deno export to npm tools: oguimbal/immutable-js-deno#2

[jdeniau]

Hi,

If you are willing to work on this, feel free to open a PR. I do not know deno at all.

[uriva]

After some investigation, there are two issues:

1. auto deploy to deno land - somehow automate what goes on in https://github.com/oguimbal/immutable-js-deno/. It's a directory that installs immutable via npm and exposes it using a mod.ts file. Then a webhook needs to be set up https://deno.land/x and it tracks each release and updates. The problem is it relies on the code being actually in the repo I believe, so not sure how to do that besides manually building.
2. some issue related to dnt, which is a tool that exports deno packages to npm (confusing I know). while using dnt to export a module using https://github.com/oguimbal/immutable-js-deno, some type checking related errors occur. I don't know how to solve this because I don't understand the errors. I've opened an issue with dnt about this Declaration emit for this file requires using private name denoland/dnt#328