Where can I get help for developing extensions for Chromium Edge?

[Deleted]

I'm trying to port my Firefox extension to Edge. But I have faced some problems even when using Extension-Polyfill from Mozilla.

1. Where is the new Edge API docs for extensions? Or shall I refer to Chromium API docs? 

2. I discovered that Edge doesn't support promise based API calls and the standard "browser" keyword like in Firefox. Is this feature planned to be included? 

[#2]

Hi,
you can find more info from here:
https://developer.microsoft.com/en-us/microsoft-edge/extensions/

Documentations: (use the left side list to browse)
https://docs.microsoft.com/en-us/microsoft-edge/extensions-chromium/

[#3]

I see this has been addressed by hotcakes. So I'll leave this in his hands. He has answered your questions and it's my confident opinion that if other questions come to the forefront he can answer them quickly.