Add dev container

[nojaf]

It would be great if this repository had a devcontainer with all the requirements included.

Then people can just clone the repo and spin a container that has all the bits they need to compile everything.

If approved, I'm willing to contribute this (although I'll might have some questions)

[cometkim]

I agree that this would be useful, but I think most of the contributors are not very familiar with it.

As far as I know, including the devcontainer in the project path is optional, and can be provided in a different path. Perhaps you can have a devcontainer image from a separate project and introduce it here.

[nojaf]

I can give this a shot but I'm rather fuzzy on what needs to happen in https://github.com/rescript-lang/rescript-compiler/blob/master/CONTRIBUTING.md#setup

C compiler toolchain and opam are tricky for me.
What exactly would that be in say Ubuntu/Debian terms?
(For opam, the proper initial setup is confusing to me)

[cknitt]

@nojaf I added a Dockerfile in #6951 - can you take it from here and create the dev container definition?

[nojaf]

@cknitt yes, thank you, I'm already playing with this in https://github.com/nojaf/rescript-compiler/tree/devcontainer.

Are you ok with some changes to the Dockerfile? One I think we need is having a separate user because dev containers don't work well when the user is root. Would it be ok to move the Dockerfile into the .devcontainer folder?

[cknitt]

Yes, please feel free to make any required changes. 👍