Windows installer

Stream: general

[Neil Strickland]

I made an attempt at a Windows installer, which you can find (for the moment) at http://bim.shef.ac.uk/lean/installer.html. It installs Git, Elan with nightly, VS Code, and the Lean extension, then it sets up a project directory with mathlib + a few sample files, then it opens that directory in VS Code. At this stage I would only recommend it to people who already know what they are doing. The installer does not currently tidy up after itself: it will leave a bunch of stuff in C:\Program Files (x86)\Lean installer, including a log file, so that is a good place to look if something goes wrong. If you try it, please let me know how it goes. There is relevant code at https://github.com/NeilStrickland/lean_installer.