Inserts a file into the editor (at the current selection position in text% editors).
The content of an editor can be changed by the system in response to other method calls, and such changes do not go through this method; use on-insert in text% or on-insert in pasteboard% to monitor content additions changes.
For more information on file formats, see load-file. If show-errors? is #f, error messages in loading the file (printed to stdout) are suppressed.