Add ,xref.5, a file supplied by The Open Group

This is a mapping file that maps name strings to references to other
sections of the [POSIX.1] standard. In the 2013 iteration, this file
was called ",xrefs.6"; now it is called ",xrefs.5".

From Felix Janda's 2015 description:

    [...] there are (naturally) a lot of references to other sections of
    the POSIX.1-2008 standard. Sections, tables and lists are labeled with
    lines starting with ".xR" and referenced using lines starting with
    ".cX". I don't have the sources for the many references to the Base
    Definitions volume, the System Interfaces volume and the Shell and
    Utilities volume of POSIX.1-2008. It would be very helpful to have
    these sources in order to read of the Section/Table/List titles and
    possibly to figure out their numbers.

Signed-off-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
1 file changed
tree: 722ca44d609d772ac4495721a357474d08c0673d
  1. ,xref.1.awk
  2. ,xref.5
  3. ,xref.py
  4. _strings.def
  5. _strings.sed
  6. posix.py
  7. README