WPF-964926 : Enhance RibbonTab Header Customization Documentation with Code Example and UI Screenshot

[SekarSivalingam]

Description

Updated the Customizing the Header in RibbonTab section of the WPF Ribbon control User Guide documentation.

1.Added a complete example demonstrating how to customize the header of multiple RibbonTab elements using the ContentTemplate property.
2.Included vector-based icons and caption text for the HOME, SEND/RECEIVE, and FOLDER tabs.
3.Added output screenshot of the customized UI to visually demonstrate the result of the customization.

Task and Ticket

Task: https://dev.azure.com/EssentialStudio/Mobile%20and%20Desktop/_workitems/edit/964926/
Ticket: https://support.syncfusion.com/agent/tickets/709759

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: WPF-964926-CaptionTemplate-Customization

[SyncfusionBuild]

CI Status: FAILURE ❌
Source Compilation: SUCCESS ✅
Failure Reason: CI Failure with violation
Build Location: WPF-964926-CaptionTemplate-Customization
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 1
Image Size Error(s): 0
Image Name Error(s): 0
Front matter Error(s): 1
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: WPF-964926-CaptionTemplate-Customization

[SyncfusionBuild]

CI Status: FAILURE ❌
Source Compilation: SUCCESS ✅
Failure Reason: CI Failure with violation
Build Location: WPF-964926-CaptionTemplate-Customization
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
Front matter Error(s): 1
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0