dotnet new gitignore
dotnet new sln -o AoC2020
dotnet new classlib -lang "F#" -o src/AocHelper
dotnet sln add .\src\AocHelper\AocHelper.fsproj
dotnet new console -lang "F#" -o src/DayN
dotnet add .\src\DayN\DayN.fsproj reference .\src\AocHelper\AocHelper.fsproj
dotnet sln add .\src\DayN\DayN.fsproj
Assuming you are at root of aoc2020 folder:
dotnet build
dotnet run --project .\src\DayN\DayN.fsproj