Update default settings.json experience (#5217)

## Summary of the Pull Request
Add comments and settings to settings.json for discoverability.

## PR Checklist
* [X] Closes #5187 
* [X] Closes #5188 
* [X] Closes #3058

src/cascadia/TerminalApp/userDefaults.json

@@ -1,30 +1,42 @@
-// This file was generated by %PRODUCT% %VERSION%
+// This file was initially generated by %PRODUCT% %VERSION%
+// It should still be usable in newer versions, but newer versions might have additional
+// settings, help text, or changes that you will not see unless you clear this file
+// and let us generate a new one for you.
 
 // To view the default settings, hold "alt" while clicking on the "Settings" button.
 // For documentation on these settings, see: https://aka.ms/terminal-documentation
-
 {
     "$schema": "https://aka.ms/terminal-profiles-schema",
 
     "defaultProfile": "%DEFAULT_PROFILE%",
 
+    // You can add more global application settings here.
+    // To learn more about global settings, visit https://aka.ms/terminal-global-settings
+
+    // If enabled, selections are automatically copied to your clipboard.
+    "copyOnSelect": false,
+
+    // A profile specifies a command to execute paired with information about how it should look and feel.
+    // Each one of them will appear in the 'New Tab' dropdown,
+    //   and can be invoked from the commandline with `wt.exe -p xxx`
+    // To learn more about profiles, visit https://aka.ms/terminal-profile-settings
     "profiles":
     {
         "defaults":
         {
-            // Put settings here that you want to apply to all profiles
+            // Put settings here that you want to apply to all profiles.
         },
         "list":
         [
             {
-                // Make changes here to the powershell.exe profile
+                // Make changes here to the powershell.exe profile.
                 "guid": "{61c54bbd-c2c6-5271-96e7-009a87ff44bf}",
                 "name": "Windows PowerShell",
                 "commandline": "powershell.exe",
                 "hidden": false
             },
             {
-                // Make changes here to the cmd.exe profile
+                // Make changes here to the cmd.exe profile.
                 "guid": "{0caa0dad-35be-5f56-a8ff-afceeeaa6101}",
                 "name": "%COMMAND_PROMPT_LOCALIZED_NAME%",
                 "commandline": "cmd.exe",
@@ -33,10 +45,28 @@
         ]
     },
 
-    // Add custom color schemes to this array
+    // Add custom color schemes to this array.
+    // To learn more about color schemes, visit https://aka.ms/terminal-color-schemes
     "schemes": [],
 
-    // Add any keybinding overrides to this array.
-    // To unbind a default keybinding, set the command to "unbound"
-    "keybindings": []
+    // Add custom keybindings to this array.
+    // To unbind a key combination from your defaults.json, set the command to "unbound".
+    // To learn more about keybindings, visit https://aka.ms/terminal-keybindings
+    "keybindings":
+    [
+        // Copy and paste are bound to Ctrl+Shift+C and Ctrl+Shift+V in your defaults.json.
+        // These two lines additionally bind them to Ctrl+C and Ctrl+V.
+        // To learn more about selection, visit https://aka.ms/terminal-selection
+        { "command": {"action": "copy", "singleLine": false }, "keys": "ctrl+c" },
+        { "command": "paste", "keys": "ctrl+v" },
+
+        // Press Ctrl+Shift+F to open the search box
+        { "command": "find", "keys": "ctrl+shift+f" },
+
+        // Press Alt+Shift+D to open a new pane.
+        // - "split": "auto" makes this pane open in the direction that provides the most surface area.
+        // - "splitMode": "duplicate" makes the new pane use the focused pane's profile.
+        // To learn more about panes, visit https://aka.ms/terminal-panes
+        { "command": { "action": "splitPane", "split": "auto", "splitMode": "duplicate" }, "keys": "alt+shift+d" }
+    ]
 }