The file was originally named `higan-config.md` because the dialog box
it described was called "higan Configuration", which was because the
menu-item to open it was in a menu called "Settings" and it would have
been weird to have a "Settings" item in a "Settings" menu.
Now there are individual menu-items for each tab in the Settings dialog,
none of which are named Settings, so the dialog has been renamed back to
"Settings", and the filename should match.
For Windows documentation, "folder" is the correct term. For generic
documentation, probably either would do but I suspect people are
slightly more likely to be familiar with "folder".