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.

tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "es5",
+    "forceConsistentCasingInFileNames": true,
+    "module": "esnext",
+    "moduleResolution": "node",
+    "jsx": "react",
+    "declaration": true,
+    "sourceMap": true,
+    "experimentalDecorators": true,
+    "skipLibCheck": true,
+    "typeRoots": ["./node_modules/@types", "./node_modules/@microsoft"],
+    "types": ["es6-promise", "webpack-env"],
+    "lib": ["es5", "dom", "es2015.collection"]
+  }
+}
+