macOS and Linux builds, WebGL fail

I added macOS and Linux builds - nothing was changed. Windows version remains official jam version.

I tried to make a WebGL build but that one doesn't work. At least one jammer who also used Unity 2020 Alpha seems to have had the same issue. This is too bad.

Having had tried to test/review as many games as possible for this jam, I now realize how valuable a web build can be.

Also less of an effort regarding virus checks.