Add Docker Image for easier setup

[Faizan-Alam-1]

I would like to propose adding a Docker image to the project.

It will be easier for contributors and users to set up and run the project since they won't have to manually install dependencies.

I would be glad to work on this and create a pull request if the maintainers agree.

[bdarnell]

What exactly are you thinking of here? As a library rather than an executable Tornado is not something users "run" - you use it by adding it to your own dependencies, not in an independent container.

For contributors, we do have a few dependencies (notably getting the right version of black and mypy), but in my experience it's easier to handle those with a virtualenv instead of a container (except for vscode's "devcontainer" integration, but I'd strongly prefer to keep tornado's main repos editor/tool-agnostic)

[Faizan-Alam-1]

Yes you right ,
I am very new to the open source community. I used this library several times in my Django project. I really wanted to give back to the community by contribution. Could you please assign me a beginner friendly task?

[bdarnell]

Over the years we've had more beginners than beginner-friendly tasks, so it might not be easy to find something appropriate. Looking back over the current list, #2935 is an easy one. Some others that should be fairly easy (but I haven't looked closely) include #2905, #2742, and #2655. Or you could go through the open issues and see if any look particularly interesting to you.