Use OS-Specific dotnet Path

[steviegt6]

See my comment in DragonLens.csproj for finer details of the problem and solution.

The Problem

Editors such as Rider do not automatically handle paths like Visual Studio does, so launching with dotnet on Windows will not work because the file is actually dotnet.exe.

The Solution

Check the current operating system and change the path accordingly (done in the project file).

[ScalarVector1]

This seems like something that should go up to https://github.com/tModLoader/tModLoader