Help: one click opens the manual, two quick clicks the note; the manual styled

One click on Help shows the explanations of every command in one
window, the names in a sans-serif and the explanations in a serif, with
a 2em margin; Copy copies them as plain text.  Two quick clicks show
the note about the documentation site.  The closed window is not
displayed (a layout rule had shown it empty on the start screen).

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

client/index.html

@@ -133,8 +133,8 @@
     </div>
     <button id="session_button" type="button"
             data-help="Who is here, and the invitation to send to others.">Session</button>
-    <button id="help" type="button" data-help="Where to read about Kokkoja. With Ctrl (Command on a Mac) held, the explanations of every command in one text.">Help</button>
-    <div id="help_popup" class="popup help_popup" hidden>Help is coming!</div>
+    <button id="help" type="button" data-help="One click shows the explanations of every command, as one text in a window. Two quick clicks show where the documentation is.">Help</button>
+    <div id="help_popup" class="popup help_popup" hidden>Documentation website coming soon!</div>
     </div>
   </header>
   <div id="notice" class="notice" hidden></div>
@@ -184,7 +184,7 @@
             data-help="Copy this text.">Copy</button>
     <button id="manual_close" type="button" aria-label="Close">×</button>
   </header>
-  <pre id="manual_text" class="manual_text" tabindex="0" autofocus></pre>
+  <div id="manual_text" class="manual_text" tabindex="0" autofocus></div>
 </dialog>
 
 <dialog id="notebook_chooser" class="chooser">