Local storage änderungen in docs/Formular.md

docs/Formular.md

@@ -31,4 +31,41 @@ This part of the BMI calculator is responsible for **user input**. Users can ent
 3. Click "BMI berechnen"
 4. Result is displayed and saved
 5. On reload: Data is still there
-6. "Clear/Reset" deletes all data
+6. "Clear/Reset" deletes all data
+
+
+## 💾 LocalStorage
+
+**Speicherort:** `localStorage['bmiData']`
+
+Daten werden nach der Berechnung als JSON-String gespeichert:
+
+```json
+{
+    "age": "25",
+    "date": "2025-02-23",
+    "weight": "75",
+    "height": "180",
+    "bmi": 23.1,
+    "category": "Normalgewicht",
+    "timestamp": "2025-02-23T14:30:45.123Z"
+}
+```
+
+### Daten extrahieren
+```javascript
+// Einfaches Auslesen
+const data = JSON.parse(localStorage.getItem('bmiData'));
+console.log(data.bmi, data.category);
+
+// Mit Null-Check
+if (localStorage.getItem('bmiData')) {
+    const data = JSON.parse(localStorage.getItem('bmiData'));
+    console.log('Gespeicherte Daten:', data);
+}
+```
+
+### Daten löschen
+```javascript
+localStorage.removeItem('bmiData');
+```