[Snek] [keith-packard/snek] 54a879: doc: Get current version number into Snek startup ...

[Keith Packard]

  Branch: refs/heads/master
  Home:   https://github.com/keith-packard/snek
  Commit: 54a879f61f322ff6a96de640097e5820c2bfff5b
      https://github.com/keith-packard/snek/commit/54a879f61f322ff6a96de640097e5820c2bfff5b
  Author: Keith Packard <keithp at keithp.com>
  Date:   2019-03-07 (Thu, 07 Mar 2019)

  Changed paths:
    M doc/Makefile
    M doc/snek.adoc

  Log Message:
  -----------
  doc: Get current version number into Snek startup message example

That involved changing how the version was passed to asciidoctor and
figuring out how to enable attribute substitution inside the relevant
paragraph.

Signed-off-by: Keith Packard <keithp at keithp.com>