docs: the readouts dock, the cursors and measurement pages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -88,11 +88,13 @@
       </item>
       <item>
         <title>The side panel</title>
-        <p>Two tabs. <gui>Measure</gui> holds the cursors readout and the measurements
-        derived from it; <gui>Signals</gui> holds the trigger and the channel list, where a
-        math channel is a row of that one list under a <gui>MATH</gui> heading whose
-        <gui>+</gui> creates one. One row per channel: its colour, an enable switch, its name
-        and its unit. A channel's badge in the badge bar is dragged onto a plot row.</p>
+        <p>A read-only copy of the cursors and of the measurements; the <gui>Edit</gui> button
+        beside each heading opens that instrument's full panel over the plot. The channel
+        list and the trigger are panels of their own, opened from the badge bar and the
+        toolbar, where a math channel is a row of the one list under a <gui>MATH</gui>
+        heading whose <gui>+</gui> creates one. One row per channel: its colour, an enable
+        switch, its name and its unit. A channel's badge in the badge bar is dragged onto a
+        plot row.</p>
       </item>
       <item>
         <title>The plot</title>