add instructions for running on mac

[esfalsa]

I think I figured out how to run Henson on a Mac. It's a bit jank — the 'proper' way to do it is probably to distribute an application bundle, from what I can tell — but at least it works.

The arm64 builds don't currently work on Macs running Apple Silicon software, since System.Data.Sqlite.Core doesn't have Apple Silicon support, hence the notes to avoid the arm64 build and to avoid using the arm64 .NET versions.

[NotAName320]

Thanks for this, I'll merge. As for the two things you brought up:

1. I'll look into packaging a .app for the next release, but signing it is out of the question as long as I don't have access to a Mac. Perhaps you could distribute your own builds?
2. I'll consider changing to Microsoft.Data.Sqlite which has arm64 support if there is demand for an arm64 build, but I'll omit arm64 builds in future releases.

[esfalsa]

I'll look into the code signing when I get a chance (it looks like a bit of a pain, even with a Mac 😅). For what it's worth, I don't think the security warnings are that unusual — I've definitely used apps before that came with those, because notarization requires a $99-a-year Apple developer subscription. The note about a 'series of errors' is just because my Mac decided to warn me about every .dll being used.

[NotAName320]

Best of luck with it!