doc: modernise everyday.txt wording and format in man page style

Refresh the contents of everyday.txt contents to a more modern
command style. Also update the mark-up so that it can be formatted
as a man page with AsciiDoc ready for transfer to the Git guides.
The transfer is in subsequent commits.

Guidance on modernising the command style provided by Junio at [1],
[2] and [3].

[1] Individual Developer, both Standalone and Participant
http://article.gmane.org/gmane.comp.version-control.git/254269
[2] Integrator
http://article.gmane.org/gmane.comp.version-control.git/254502
[3] Administrator
http://article.gmane.org/gmane.comp.version-control.git/254824

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: Makefile regularise OBSOLETE_HTML list building

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: add 'everyday' to 'git help'

The "Everyday GIT With 20 Commands Or So" is not accessible via the
Git help system.  Move everyday.txt to giteveryday.txt so that "git
help everyday" works, and create a new placeholder file everyday.html
to refer people who follow existing URLs to the updated location.

giteveryday.txt now formats well with AsciiDoc as a man page and
refreshed content to a more command modern style.

Add 'everyday' to the help --guides list and update git(1) and 5
other links to giteveryday.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>