Improve the MS-Windows appendix of the Emacs manual
* doc/emacs/msdos.texi (Windows Startup): Describe the pinned
shortcuts for starting Emacs.
(Text and Binary): Minor wording changes.
(Windows Files): Mention 'read-file-name-completion-ignore-case'.
(ls in Lisp): Update the list of supported 'ls' switches.
Document 'ls-lisp-use-string-collate' and
'ls-lisp-UCA-like-collation'.
(Windows HOME): Mention warnings displayed at startup when
deprecated locations of HOME and/or deprecated names for init
files are used.
(Windows Keyboard): Mention delete-selection-mode.