Fixed firefox compatibility and added missing icons to feature pages (#2863)

# Description of Changes

Fixed icon incompatibility with firefox
Added missing icons to feature pages

Closes #(2833)


![image](https://github.com/user-attachments/assets/51ba008a-f6ab-4e29-9a79-99d85d152689)


---

## Checklist

### General

- [ x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ x] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [ x] I have performed a self-review of my own code
- [ x] My changes generate no new warnings

### Documentation

- [ x] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ x] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ x] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ x] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

Co-authored-by: Reece Browne <reece@stirling.pdf>

src/main/resources/templates/auto-split-pdf.html

@@ -17,7 +17,9 @@
         <div class="row justify-content-center">
           <div class="col-md-6 bg-card">
             <div class="tool-header">
-              <span class="material-symbols-rounded tool-header-icon advance">cut</span>
+              <svg class="material-symbols-rounded tool-header-icon advance">
+                <use xlink:href="/images/split-auto.svg#icon-split-auto"></use>
+              </svg>
               <span class="tool-header-text" th:text="#{autoSplitPDF.header}"></span>
             </div>