[Excel] (Custom Functions) Add unified manifest note to all articles (#4824)

* Update Excel React quickstart manifest reference, match language to jQuery quickstart

* Add unified manifest to custom functions note, begin updating Excel tutorial

* Undo date change

* Adjust note

* Change manifest note wording

* Change manifest note wording

* Update date in Excel React quickstart

* Update date in Excel tutorial documentation

---------

Co-authored-by: Rick Kirkham <[email protected]>

Author: alison-mk

docs/includes/excel-custom-functions-note.md

@@ -12,3 +12,6 @@
 >
 > - Office on iPad
 > - volume-licensed perpetual versions of Office 2019 or earlier on Windows
+
+> [!NOTE]
+> The unified manifest for Microsoft 365 doesn't currently support custom functions projects. You must use the add-in only manifest for custom functions projects. For more information, see [Office Add-ins manifest](../develop/add-in-manifests.md).

docs/quickstarts/excel-quickstart-react.md

@@ -1,7 +1,7 @@
 ---
 title: Use React to build an Excel task pane add-in
 description: Learn how to build a simple Excel task pane add-in by using the Office JS API and React.
-ms.date: 12/11/2023
+ms.date: 02/12/2025
 ms.service: excel
 ms.localizationpriority: high
 ---
@@ -31,7 +31,7 @@ After you complete the wizard, the generator creates the project and installs su
 
 The add-in project that you've created with the Yeoman generator contains sample code for a basic task pane add-in. If you'd like to explore the key components of your add-in project, open the project in your code editor and review the files listed below. When you're ready to try out your add-in, proceed to the next section.
 
-- The **manifest.xml** file in the root directory of the project defines the settings and capabilities of the add-in. To learn more about the **manifest.xml** file, see [Office Add-ins with the add-in only manifest](../develop/xml-manifest-overview.md).
+- The **./manifest.xml** or **manifest.json** file in the root directory of the project defines the settings and capabilities of the add-in.
 - The **./src/taskpane/taskpane.html** file defines the HTML framework of the task pane, and the files within the **./src/taskpane/components** folder define the various parts of the task pane UI.
 - The **./src/taskpane/taskpane.css** file contains the CSS that's applied to content in the task pane.
 - The **./src/taskpane/components/App.tsx** file contains the Office JavaScript API code that facilitates interaction between the task pane and Excel.

docs/tutorials/excel-tutorial.md

@@ -1,7 +1,7 @@
 ---
 title: Excel add-in tutorial
 description: Build an Excel add-in that creates, populates, filters, and sorts a table, creates a chart, freezes a table header, protects a worksheet, and opens a dialog.
-ms.date: 01/07/2025
+ms.date: 02/12/2025
 ms.service: excel
 #Customer intent: As a developer, I want to build a Excel add-in that can interact with content in a Excel document.
 ms.localizationpriority: high
@@ -475,6 +475,19 @@ In this step of the tutorial, you'll add a button to the ribbon that toggles wor
 
 ### Configure the manifest to add a second ribbon button
 
+There are two manifest options for Office Add-ins: the unified manifest for Microsoft 365, and the add-in only manifest.
+
+# [Unified manifest for Microsoft 365](#tab/jsonmanifest)
+
+> [!NOTE]
+> The unified manifest for Microsoft 365 is currently in public developer preview for Excel and shouldn't be used in production Excel add-ins. We invite you to try it out in test or development environments. Use the add-in only manifest for production Excel add-ins.
+
+1. Open the manifest file **./manifest.json**.
+
+1. (More steps TBD)
+
+# [Add-in only manifest](#tab/xmlmanifest)
+
 1. Open the manifest file **./manifest.xml**.
 
 1. Locate the **\<Control\>** element. This element defines the **Show Taskpane** button on the **Home** ribbon you have been using to launch the add-in. We're going to add a second button to the same group on the **Home** ribbon. In between the closing **\</Control\>** tag and the closing **\</Group\>** tag, add the following markup.