[css-writing-modes] Restore image lost in <https://hg.csswg.org/drafts/diff/bad54742d675/css-writing-modes/Overview.bs>, update captions

Author: fantasai

css-writing-modes/Overview.bs

@@ -1620,20 +1620,27 @@ Line-relative Directions</h3>
   <p>See the <a href="#logical-to-physical">table below</a> for the exact
     mappings between physical and line-relative directions.
 
-  <div class="figurepair">
-    <div class="figure">
+  <div class="figure">
     <a href="diagrams/line-orient-up.svg">
       <img src="diagrams/line-orient-up.png" class="landscape"
         alt="Line orientation compass"></a>
-    <p class="caption">Line orientation compass</p>
-    </div>
+    <p class="caption">Line orientation in ''horizontal-tb''</p>
+  </div>
 
-    <div class="figure">
+  <div class="figurepair">
+  <div class="figure">
     <a href="diagrams/line-orient-right.svg">
       <img src="diagrams/line-orient-right.png" class="portrait"
         alt="Typical orientation in vertical"></a>
-      <p class="caption">Typical orientation in vertical</p>
-    </div>
+      <p class="caption">Line orientation in ''vertical-rl'', ''vertical-lr'', and ''sideways-rl''</p>
+  </div>
+
+  <div class="figure">
+    <a href="diagrams/line-orient-left.svg">
+      <img src="diagrams/line-orient-left.png" class="portrait"
+        alt="Typical orientation in vertical"></a>
+      <p class="caption">Line orientation in ''sideways-lr''</p>
+  </div>
   </div>
 
   <div class="note">