katom types from ref/ in groups, @table :leading in lines of text and :rulesep, @code under txt, one table style attribute, literal-klammer options (from dev 2e453744f5e9)

kdesc --katoms is Klammertext rendered from ref/, the types in titled groups,
with --katoms full for the regex column.  @table :leading L is L lines of the
surrounding text in html as in pdf (default 1), and :rulesep spaces the
horizontal rules.  The html table has one style attribute, so :column_width
fractions take effect again.  @code and @source_listing render in plain
text; captions are numbered per kind there, and a table needs no blank line
around it.  @c takes :nd, and an option-shaped word before a bar inside
literal code is code.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

sks/code/css/code.css

@@ -30,7 +30,11 @@
 .code_block {
     display: flex;
     align-items: center;
-    margin: 0 0 0 1rem;
+    /* No left margin: it was 1rem, an html-only inset with no tex
+       counterpart, which set the code a rem to the right of its own
+       flush-left caption and of the same listing's pdf.  A listing's
+       inset is :offset, in both targets (the hpos_margin precedent). */
+    margin: 0;
     padding: 0;
 }