Add Accordion web part implementation with dynamic SharePoint list integration

- Created Accordion web part with SPFx 1.4.1 framework.
- Implemented dynamic loading of SharePoint lists and fields.
- Added configuration options for title, content, and category fields.
- Included support for multiple open sections and initial state settings.
- Developed HTML sanitizer for rich text content.
- Implemented accessible accordion UI with category grouping.
- Added localization support for English and German languages.
- Created necessary configuration files for deployment and asset management.
- Added validation script to ensure project compliance with standards.

.yo-rc.json

@@ -0,0 +1,12 @@
+{
+  "@microsoft/generator-sharepoint": {
+    "version": "1.4.1",
+    "libraryName": "accordion",
+    "libraryId": "27a6fd90-42a1-4e39-8862-08ed0e7803bc",
+    "environment": "onprem",
+    "packageManager": "npm",
+    "solutionName": "accordion",
+    "componentType": "webpart"
+  }
+}
+