Consider adding a WT_PROFILE env var pointing to settings file

If the settings UI is not planned until after 1.0, then I strongly recommend adding an environment variable with the path to the json settings file, so it can be edited with the editor of choice (vi, notepad, nano, emacs, whatever) from within the shell of choice without burning brain calories trying to find it buried in AppData. Also: Relying on the GUI menu is, well, unreliable, due to there being no guarantee of a valid file association for json files.

We've already got WT_SESSION env var -- something like WT_PROFILE would be useful.

Then from within cmd or powershell, I can easily edit settings with my preferred editor, or interactively using $settings = gc $env:WT_PROFILE | convertto-json and flipping settings on the object model directly before saving it back out.