Draft: Update index.md - updated instructions inline with current version

Lines 19 - 23 Added instructions for opening preferences dialog on Mac Added “Windows or Linux” to existing instructions

Line 33 Removed “location” from “Expanding the Folders (click the “+”) in the left pane of the dialog will expose the various asset folder locations:” Expanding the folders doesn’t expose the folder locations.

Lines 70 - 72 Moved fifth button description onto next line and added 6th button description (“Show file location in the file manager”)

Lines 86 - 88 Added instructions for refreshing assets