script to download and install latest godot pre-release build to godot and then create a symbolic link godot/godot that executes it. devcontainer installs Ubuntu with C#, kate, nano, vim and wget

With Docker on Windows, this lets you run the Linux version of godot in a devcontainer. Will test in Bazzite shortly, but should work in native Linux as well. VS Code with wsl can't forward Wayland to podman at this time, and so it does need to use Docker.