docs: added guide and updated docs for Tray (#29385)

* docs: added guide and updated docs for Tray

* docs: improve clarity

docs/tutorial/tray.md

@@ -0,0 +1,83 @@
+---
+title: Tray
+description: This guide will take you through the process of creating
+a Tray icon with its own context menu to the system's notification area.
+slug: tray
+hide_title: true
+---
+
+# Tray
+
+## Overview
+
+<!-- ✍ Update this section if you want to provide more details -->
+
+This guide will take you through the process of creating a
+[Tray](https://www.electronjs.org/docs/api/tray) icon with
+its own context menu to the system's notification area.
+
+On MacOS and Ubuntu, the Tray will be located on the top
+right corner of your screen, adjacent to your battery and wifi icons.
+On Windows, the Tray will usually be located in the bottom right corner.
+
+## Example
+
+### main.js
+
+First we must import `app`, `Tray`, `Menu`, `nativeImage` from `electron`.
+
+```js
+const { app, Tray, Menu, nativeImage } = require('electron')
+```
+
+Next we will create our Tray. To do this, we will use a
+[`NativeImage`](https://www.electronjs.org/docs/api/native-image) icon,
+which can be created through any one of these
+[methods](https://www.electronjs.org/docs/api/native-image#methods).
+Note that we wrap our Tray creation code within an
+[`app.whenReady`](https://www.electronjs.org/docs/api/app#appwhenready)
+as we will need to wait for our electron app to finish initializing.
+
+```js title='main.js'
+let tray
+
+app.whenReady().then(() => {
+  const icon = nativeImage.createFromPath('path/to/asset.png')
+  tray = new Tray(icon)
+
+  // note: your contextMenu, Tooltip and Title code will go here!
+})
+```
+
+Great! Now we can start attaching a context menu to our Tray, like so:
+
+```js
+const contextMenu = Menu.buildFromTemplate([
+  { label: 'Item1', type: 'radio' },
+  { label: 'Item2', type: 'radio' },
+  { label: 'Item3', type: 'radio', checked: true },
+  { label: 'Item4', type: 'radio' }
+])
+
+tray.setContextMenu(contextMenu)
+```
+
+The code above will create 4 separate radio-type items in the context menu.
+To read more about constructing native menus, click
+[here](https://www.electronjs.org/docs/api/menu#menubuildfromtemplatetemplate).
+
+Finally, let's give our tray a tooltip and a title.
+
+```js
+tray.setToolTip('This is my application')
+tray.setTitle('This is my title')
+```
+
+## Conclusion
+
+After you start your electron app, you should see the Tray residing
+in either the top or bottom right of your screen, depending on your
+operating system.
+
+```fiddle docs/fiddles/native-ui/tray
+```