docs: update 'first cut' procps.3 with revised version

docs: update 'first cut' procps.3 with revised version

This represents the 'second cut' at providing a shared
man page that supports more than one newlib interface.

In this approach, the following assumptions were made:

1) It is the kernel folks' job to document /proc files
not to mention fields within those files. And since we
don't yet know what some of those fields represent, we
shouldn't attempt to document any of those we do know.

2) Our header files serve as an essential reference in
successful exploitation of the new library interfaces.

3) The description represents functions as they appear
in the header itself making them immediately familiar.

4) Some inconsistencies among the interfaces have been
handled more visually rather than in a narrative form.

5) Armed with our header file users can easily see the
self-documenting enumerators & structures. There isn't
a need to explain them yet again in this man document.

6) Contrary to man guidelines, we shouldn't list error
codes. Simple generic guidance serves everyone better.

Reference(s):
. 05/19/20, procps.3 man page introduced
commit fc69028d374ae933b55b05b0f1418ac6a3da87e2

Signed-off-by: Jim Warner <james.warner@comcast.net>