[add]

serviceの家族情報を保存する処理を追加

src/app/services/family-service.ts

     return this.families.find((family) => family.id === id);
   }
 
-  addFamily(family: Family) {
-    this.families.push(family);
+  saveFamily(updateFamily: Family) {
+    const index = this.families.findIndex((families) => families.id === updateFamily.id);
+    if (index === -1) {
+     this.families.push(updateFamily);
+     return;
+    }
+    this.families[index] = updateFamily;
   }
   // updateFamily(family: Family);
   // deleteFamily(id: string);