VSCode provides extensive support for developing inside of a container. Their official Developing inside a Container documentation details the process. All of the logic for configuring the development container and environment lives inside this .devcontainer directory.
In summary, VSCode on your desktop will create a docker image and starts a VSCode server within it that it then connects to similar to how VSCode would remotely connect to another machine over SSH. This has the advantage of providing a consistent and well-defined coding environment (including automatic installation of recommended vscode extensions) to work within.
To make use of this feature, you'll first need to install the VSCode ms-vscode-remote.remote-containers extension. After that, whenever you Open Folder a folder that contains a .devcontainer directory, such as this biomes repository, VSCode will prompty you if you'd like to re-open it in a container, or you can open the command palette and select Remote-Containers: Open folder in container.... When you do open the container VSCode will build a docker image from .devccontainer/Dockerfile` (the result will be cached for next time) and then drop you into it. The source code will be mounted within the container from your host file system.
Ensure Docker is installed, e.g. sudo apt install docker.io.
Ensure that Docker Desktop is installed. Note that you will still find yourself in a Linux environment within the container. Docker Desktop works on these platforms by setting up a virtual machine see The Magic Behind the Scenes of Docker Desktop.
Note that there are some awkward artifacts when running with the source code bind mounted from a Windows host filesystem into a Linux docker filesystem, like bad file permissions and some latency when format-on-save is run. You should clone the repository inside of Windows Subsystem for Linux (WSL), and then from there open the folder within docker (so this would be Docker in WSL), and everything will work as expected.
See the Sharing Git credentials with your container article from Microsoft on how to set this up. In short, you'll need to start a SSH agent on your host, and VSCode will take care of forwarding that into the container. Make sure you run ssh-add on your host, so that your key is visible to the SSH agent.