pin deps/plotter: per-column x axes, tighter cell gap; docs

help/C/org.udpscope.app/layout.page

@@ -59,8 +59,8 @@
     panning along time in any of them moves all of them, and the vertical cursors are drawn in
     every plot. The plots of a split row also share one y range: the y labels are drawn at the
     left of the first plot only, the horizontal cursors sit at the same values in every plot, and a
-    zoom, pan, fit or fixed range in any of them applies to the whole row. Only the
-    bottom row carries the time labels. A row holds at most 4 plots and the figure at most 8
+    zoom, pan, fit or fixed range in any of them applies to the whole row. The time labels
+    sit under the bottom row, and under any row above it whose columns differ from the row below. A row holds at most 4 plots and the figure at most 8
     in total; the <gui>+</gui> buttons go grey at the limit.</p>
   </section>