support for non-consecutive ranges

Paints the start/end line of a range if there was no previous range.

src/renderer.typ

@@ -453,8 +453,9 @@
   let desc-y = bits-y + bit-h * 2
 
   // Names + simple descriptions
-  for range_ in ranges {
+  for (i, range_) in ranges.enumerate() {
     let start-i = to-real-i(if config.ltr-bits {range_.start} else {range_.end})
+    let end-i = to-real-i(if config.ltr-bits {range_.end} else {range_.start})
     let start-x = bits-x + start-i * bit-w
     let width = rng.bits(range_) * bit-w
 
@@ -465,6 +466,28 @@
     shapes += draw-line(border-col, (line-x, bits-y), (line-x, bits-y + bit-h))
     shapes += draw-text(range_.name, txt-col, name-x, name-y, fill: bg-col)
 
+    // paint end line only if needed
+    if (
+      start-i != 0
+        and end-i != struct.bits - 1
+        and ranges
+          .at(
+            i
+              + {
+                if config.ltr-bits and i < ranges.len() - 1 { 1 } else { -1 }
+              },
+          )
+          .end
+          != range_.start - 1
+    ) {
+      line-x += if config.ltr-bits { -width } else { width }
+      shapes += draw-line(
+        border-col,
+        (line-x, bits-y),
+        (line-x, bits-y + bit-h),
+      )
+    }
+    
     if range_.description != "" {
       let shapes_
       (shapes_, desc-x, desc-y) = draw-description(