[Snek] [keith-packard/snek] 92442a: doc: Add cross references within the reference manual

[Keith Packard]

  Branch: refs/heads/master
  Home:   https://github.com/keith-packard/snek
  Commit: 92442aec2714b86a33640aa22d7cc2e983ed0792
      https://github.com/keith-packard/snek/commit/92442aec2714b86a33640aa22d7cc2e983ed0792
  Author: Keith Packard <keithp at keithp.com>
  Date:   2019-06-09 (Sun, 09 Jun 2019)

  Changed paths:
    M doc/snek.adoc

  Log Message:
  -----------
  doc: Add cross references within the reference manual

This catches all of the 'below', 'above' and 'section' usages and provides
explicit links.

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