[Ohrrpgce] wip r13910: Add sl:sprite and sl:shadow aliases to sl:walkabout{sprite, shadow}

[cron at rpg.hamsterrepublic.com]

https://github.com/ohrrpgce/ohrrpgce/commit/e1bda331cb5ec7f6e83fbd14201fdf526d3bee4e
Author: teeemcee <teeemcee at 7d344553-34f0-0310-a9b1-970ce8f1c3a2>
Date:   Fri Jun 27 06:37:06 2025 +0000

    Add sl:sprite and sl:shadow aliases to sl:walkabout{sprite,shadow}
    
    I'm adding these constants for use in battles.
    
    I think it makes sense to have a generic sl:sprite lookup code used anywhere
    where there's a single main sprite component to a slice subtree, when providing
    the parent/subtree root slice is necessary. Walkabout and BattleSprite slices
    match that pattern. I don't see any benefit to separate codes as there's no
    chance of confusion.
    
    Got rid of one SL_EDITOR lookup in preference for that.
    

 docs/plotdict.xml        | 10 ++++++----
 docs/plotdictionary.html | 10 ++++++----
 enemyedit.bas            |  4 ++--
 plotscr.hsd              |  2 ++
 sliceedit.bas            |  5 ++---
 slices.bas               |  5 ++---
 slices.bi                |  7 ++++---
 whatsnew.txt             |  2 ++
 8 files changed, 26 insertions(+), 19 deletions(-)