docs: uniformize module API doc format (#28920)

This PR ensures that all API modules are present in the README doc,
as there were a couple missing. It also formats all modules to contain
a level-1 heading and a blockquote description.

docs/README.md

@@ -126,6 +126,8 @@ These individual tutorials expand on topics discussed in the guide above.
 * [ipcMain](api/ipc-main.md)
 * [Menu](api/menu.md)
 * [MenuItem](api/menu-item.md)
+* [MessageChannelMain](api/message-channel-main.md)
+* [MessagePortMain](api/message-port-main.md)
 * [net](api/net.md)
 * [netLog](api/net-log.md)
 * [nativeTheme](api/native-theme.md)
@@ -135,6 +137,7 @@ These individual tutorials expand on topics discussed in the guide above.
 * [protocol](api/protocol.md)
 * [screen](api/screen.md)
 * [session](api/session.md)
+* [ShareMenu](api/share-menu.md)
 * [systemPreferences](api/system-preferences.md)
 * [TouchBar](api/touch-bar.md)
 * [Tray](api/tray.md)

docs/api/browser-view.md

@@ -1,14 +1,16 @@
-## Class: BrowserView
-
-> Create and control views.
-
-Process: [Main](../glossary.md#main-process)
+# BrowserView
 
 A `BrowserView` can be used to embed additional web content into a
 [`BrowserWindow`](browser-window.md). It is like a child window, except that it is positioned
 relative to its owning window. It is meant to be an alternative to the
 `webview` tag.
 
+## Class: BrowserView
+
+> Create and control views.
+
+Process: [Main](../glossary.md#main-process)
+
 ### Example
 
 ```javascript

docs/api/menu.md

@@ -1,3 +1,5 @@
+# Menu
+
 ## Class: Menu
 
 > Create native application menus and context menus.

docs/api/message-channel-main.md

@@ -9,12 +9,15 @@ channel messaging.
 
 ## Class: MessageChannelMain
 
+> Channel interface for channel messaging in the main process.
+
 Process: [Main](../glossary.md#main-process)
 
 Example:
 
 ```js
 // Main process
+const { MessageChannelMain } = require('electron')
 const { port1, port2 } = new MessageChannelMain()
 w.webContents.postMessage('port', null, [port2])
 port1.postMessage({ some: 'message' })

docs/api/message-port-main.md

@@ -14,6 +14,8 @@ channel messaging.
 
 ## Class: MessagePortMain
 
+> Port interface for channel messaging in the main process.
+
 Process: [Main](../glossary.md#main-process)
 
 ### Instance Methods

docs/api/share-menu.md

@@ -1,8 +1,4 @@
-## Class: ShareMenu
-
-> Create share menu on macOS.
-
-Process: [Main](../glossary.md#main-process)
+# ShareMenu
 
 The `ShareMenu` class creates [Share Menu][share-menu] on macOS, which can be
 used to share information from the current context to apps, social media
@@ -11,6 +7,12 @@ accounts, and other services.
 For including the share menu as a submenu of other menus, please use the
 `shareMenu` role of [`MenuItem`](menu-item.md).
 
+## Class: ShareMenu
+
+> Create share menu on macOS.
+
+Process: [Main](../glossary.md#main-process)
+
 ### `new ShareMenu(sharingItem)`
 
 * `sharingItem` SharingItem - The item to share.

docs/api/touch-bar.md

@@ -1,3 +1,5 @@
+# TouchBar
+
 ## Class: TouchBar
 
 > Create TouchBar layouts for native macOS applications

docs/api/tray.md

@@ -1,3 +1,5 @@
+# Tray
+
 ## Class: Tray
 
 > Add icons and context menus to the system's notification area.