* doc/emacs/building.texi (Lisp Interaction):
* doc/lispref/os.texi (Startup Summary):
* etc/NEWS: Document this.
* lisp/startup.el (initial-scratch-message):
Look up find-file’s key rather than hardcoding it.
(command-line-1): Substitute the doc string.
This also substitutes the quotes, which will help test display
quoting at startup.