Add actionButton.define "command" attribute

This automatically triggers a command bound to an actionButton, and
notably also shows the keyboard shortcut connected to it (if any)

libraries/Library/Std/APIs/Action Button.md

@@ -10,21 +10,28 @@ APIs to more conveniently define action buttons (alternative to setting them via
 Keys to define:
 
 * `icon`: [feather icon](https://feathericons.com) to use for your button
-* `run`: function to invoke once the button is pushed
+* `command` (optional): command name to invoke when clicked. When set, the command's keyboard shortcut is automatically shown in the tooltip. Replaces `run`.
+* `run` (optional): function to invoke once the button is pushed. Use this for custom logic that doesn't map to a single command.
 * `description` (optional): description of button (appears on hover)
 * `priority` (optional): determines priority of button (the higher, the earlier in the list)
 * `mobile`: when set to `true` this button will only appear on mobile devices
 * `standalone`: when set to `true` this button will only appear in standalone/PWA mode; when `false`, only in browser mode
 * `dropdown` (optional): when set to `false`, the button stays visible outside the dropdown menu on mobile (default: `true`)
 
-# Example
+Either `command` or `run` should be specified.
+
+# Examples
 ```lua
--- Defines a new button that forces your UI into read-only mode
+-- Bind a button to a command (keyboard shortcut shown on hover)
+actionButton.define {
+  icon = "pen-tool",
+  description = "Start journaling",
+  command = "Journal: Today",
+}
+
+-- Custom button with a run function
 actionButton.define {
   icon = "eye",
-  -- Uncomment the following line to only make this button appear 
-  -- ONLY on mobile devices:
-  --   mobile = true,
   run = function()
     editor.setUiOption("forcedROMode", true)
     editor.rebuildEditorState()

libraries/Library/Std/Config.md

@@ -358,6 +358,10 @@ config.define("actionButtons", {
         type = "string",
         description = "Optional description of the action button"
       },
+      command = {
+        type = "string",
+        description = "Optional command name to invoke when clicked (replaces run). The command's keyboard shortcut is automatically shown in the tooltip."
+      },
       priority = {
         type = "number",
         description = "Optional priority: the higher the earlier the button will appear in the list"
@@ -376,7 +380,7 @@ config.define("actionButtons", {
       },
       run = schema.func(),
     },
-    required = {"icon", "run"},
+    required = {"icon"},
     additionalProperties = false
   }
 })
@@ -399,28 +403,22 @@ config.set {
     {
       icon = "home",
       description = "Go to the index page",
+      command = "Navigate: Home",
       priority = 3,
       dropdown = false,
-      run = function()
-        editor.invokeCommand "Navigate: Home"
-      end
     },
     {
       icon = "book",
       description = "Open page",
+      command = "Navigate: Page Picker",
       priority = 2,
       dropdown = false,
-      run = function()
-        editor.invokeCommand "Navigate: Page Picker"
-      end
     },
     {
       icon = "terminal",
       description = "Run command",
+      command = "Open Command Palette",
       priority = 1,
-      run = function()
-        editor.invokeCommand "Open Command Palette"
-      end,
     },
     {
       icon = "chevron-left",