Documentation(856676): Resolved documentation issues in the Blazor ListBox Icons and Templates UG

[kathiravan4982]

Description

Documentation(856676): Fixed the following issues in the Blazor ListBox Icons and Templates UG documentation:

• Removed the unused Model variable from the Templates sample code.
• Updated the ItemTemplate API reference link to point to the correct ListBoxTemplates<TItem>.ItemTemplate API page.
• Fixed the indentation of ListBoxFieldSettings under SfListBox in both code examples.
• Added an introduction for the ItemTemplate property in the Templates section.
• Added an introduction for icon customization in the Icons section.
• Added details about the Syncfusion Blazor icons library used by the e-icons class.
• Added the ListBoxTemplates API reference link in the Templates section.
• Updated the IconCss field description with details about built-in icon classes and custom CSS classes.

Code Studio usage(Mandatory)

• Code Studio used in this PR/MR?

  • Yes
  • No

• If Yes: Primary use (choose one)

  • Generate new content
  • Refactor/improve existing content
  • Review assistance (explanations/summaries)
  • Other:

• Outcome

  • Saved time
  • Neutral
  • Cost time

• If “Cost time” explain in short (1 or 2 lines):

Type of Change

• New documentation page
• Update to existing documentation
• Bug fix (broken links, typos, formatting issues)
• Structural change (folders, navigation, index)
• Content improvement (clarity, examples, screenshots)
• Other (please describe):

Reviewer Checklist (Mandatory)

• Reviewed the provided Code Studio usages related information
• Content changes follow UG/Documentation guidelines
• All provided information reviewed and verified
• Links and previews checked

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: 856676-ListBoxUG-Hf

[SyncfusionBuild]

CI Status: FAILURE ❌
Source Compilation: SUCCESS ✅
Failure Reason: CI Failure with violation
Build Location: 856676-ListBoxUG-Hf
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

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: 856676-ListBoxUG-Hf

[SyncfusionBuild]

CI Status: SUCCESS ✅
Source Compilation: SUCCESS ✅
Build Location: 856676-ListBoxUG-Hf
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): 0
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