updated doc and snapshots for help button

Changes.txt

@@ -14,7 +14,7 @@
 
 6.5.2 to 6.5.3 (XXX, 2021)
 
-  * Added context-sensitive help (TODO: doc)
+  * Added context-sensitive help
 
   * Improved support of multiple monitors with different resolutions.
 

docs/index.html

@@ -613,6 +613,10 @@
   as the function keys and display the current state. You may find this useful if
   you cannot remember all the function key events, or you wish to use Stella
   without a keyboard (ie, in a standalone gaming system).</p>
+
+  <p>Note: Clicking the `?` at the top right opens this document at the related
+  paragraph. This works for almost all dialogs. There is also a hotkey defined
+  for help (see <b><a href="#Hotkeys">Hotkeys</a></b>)).</p>
   </blockquote></br>
 
   <h2><b><a name="Keyboard">Keyboard Layout</a></b></h2>
@@ -2172,6 +2176,11 @@
       <td>Alt + Return</td>
       <td>Cmd + Return</td>
     </tr>
+    <tr>
+      <td>Open context-sensitive help</td>
+      <td>F1</td>
+      <td>F1</td>
+    </tr>
     <tr>
       <td>Exit emulator</td>
       <td>Control + Q</td>
@@ -3922,7 +3931,7 @@
   <img src="graphics/eventmapping.png">
   <img src="graphics/eventmapping_remap.png">
 
-  <p>Finally there is a 'Combo' button in the 'Emulation Events' tab, accessible
+  <p>Finally there is a <a name="Combo"/>'Combo'</a> button in the 'Emulation Events' tab, accessible
   only when a Combo event has been selected from the list of events on the left.
   Clicking 'Combo' will show a dialog similar to the following:</p>
   <img src="graphics/eventmapping_combo.png">
@@ -4933,7 +4942,7 @@ Ms Pac-Man (Stella extended codes):
         <tr><th>&nbsp;Type&nbsp;</th><th>Description</th></tr>
         <tr><td>Joystick</td><td>Atari's famous black joystick that was originally included with the system.</td></tr>
         <tr><td>Paddles </td><td>Standard paddle controllers, only (up to 8) fire buttons supported for QuadTari.</td></tr>
-        <tr><td>Driving</td><td>Looks like a paddle, but allows 360<EFBFBD> movement. Only one unit per connector, unlike paddles which were sold in pairs.</td></tr>
+        <tr><td>Driving</td><td>Looks like a paddle, but allows 360&#176; movement. Only one unit per connector, unlike paddles which were sold in pairs.</td></tr>
         <tr><td><a href="https://atariage.com/store/index.php?l=product_detail&p=1045">AtariVox</a></td><td>A SpeakJet based unlimited-vocabulary speech/sound synthesizer with 32K EEPROM.</td></tr>
         <tr><td>SaveKey</td><td>A 32K EEPROM for saving high scores, etc. (the EEPROM portion of an AtariVox).</td></tr>
       </table></td>

src/emucore/EventHandler.cxx

@@ -3306,9 +3306,8 @@ EventHandler::MenuActionList EventHandler::ourMenuActionList = { {
 
   { Event::UIPrevDir,         "Parent directory",     "" },
   { Event::ToggleFullScreen,  "Toggle fullscreen",    "" },
-  { Event::Quit,              "Quit",                 "" },
+  { Event::UIHelp,            "Help"                  "" },
-  { Event::UIHelp,       "Help"                  "" }
+  { Event::Quit,              "Quit",                 "" }
-
 } };
 
 // Event groups

src/gui/ComboDialog.cxx

@@ -73,6 +73,8 @@ ComboDialog::ComboDialog(GuiObject* boss, const GUI::Font& font,
   addDefaultsOKCancelBGroup(wid, font);
 
   addToFocusList(wid);
+
+  setHelpAnchor("Combo");
 }
 
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src/gui/QuadTariDialog.cxx

@@ -91,6 +91,8 @@ QuadTariDialog::QuadTariDialog(GuiObject* boss, const GUI::Font& font, int max_w
 
   addDefaultsOKCancelBGroup(wid, _font);
   addBGroupToFocusList(wid);
+
+  setHelpAnchor("Quadtari");
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -