Add stack comments to existing words (from retro.muri,
retro.forth, interface/ll.retro, and interface/dedup.retro).
Words defined in the others will make use of the extended
comment format this introduces to add them inline.

~~~
{{
  :save (s-)  n:inc s:chop here swap s:keep &drop compile:call #2 + d:last.name n:dec store ;
  :stack-comment? (s-sf) dup #0 s:fetch $: eq? ;
---reveal---
  :sigil:(
    stack-comment? [ compiling? &save &drop choose ] &drop choose ;
  immediate
}}

:d:describe (:s-)
  d:lookup nl
  dup 'Name:____ s:put d:name s:put nl
  dup 'Address:_ s:put d:xt fetch n:put nl
  dup 'Class:___ s:put d:class fetch n:put nl
  dup 'Source:__ s:put d:source fetch dup n:-zero? &s:put &drop choose nl
  dup 'Stack:___ s:put d:stack fetch dup n:-zero? &s:put &drop choose nl
  drop ;
~~~