documents: lists go on, block lines shift, tables change, matches show, fences color by language

The document carries Markdown's editing tools for ElyMark (MARK-06):
Enter continues a list item or ends an empty one, Tab and Shift-Tab
shift an open block's lines, table rows and columns come and go as
one undo step, a match shows in any mode, replacements are one step,
and a fenced block colors by its language.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/documents/document/mod.rs

@@ -1,6 +1,9 @@
 mod edit;
+mod finding;
+mod lists;
 mod parse;
 mod place;
+mod tables;
 #[cfg(all(test, feature = "test-support"))]
 mod tests;
 mod visual;
@@ -16,6 +19,7 @@ use gpui::{
 
 pub use parse::DocumentHeading;
 use parse::{Parsed, alike, parsed};
+pub use tables::TableEdit;
 
 use super::{MarkdownMode, markdown::markdown_highlights, modes::joint, render::OnLink};
 use crate::{