One feature of coming C# 9 is so called top-level programs. So that you could just write the following without classes.
using System;
Console.WriteLine("Hello World!");
and dotnet run will launch it for you.
It works for me, but only if I also add a .csproj file like the one below
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net5.0</TargetFramework>
</PropertyGroup>
</Project>
Is there a way to skip .csproj from the picture? :) So that there's just a single Program.cs file and nothing more.