use localized placeholder values for text input fields

assets/i18n.json

@@ -64,7 +64,9 @@
     "creator": {
       "title": "Create New Meeting",
       "meetingNameLabel": "Meeting Name",
+      "meetingNamePlaceholder": "My Meeting",
       "meetingDescriptionLabel": "Description",
+      "meetingDescriptionPlaceholder": "Meeting description (optional)",
       "meetingStartLabel": "Start Date & Time",
       "meetingEndLabel": "End Date & Time",
       "meetingOrganizerLabel": "Organizer Email",
@@ -152,7 +154,9 @@
     "creator": {
       "title": "Neues Meeting erstellen",
       "meetingNameLabel": "Meeting-Name",
+      "meetingNamePlaceholder": "Mein Meeting",
       "meetingDescriptionLabel": "Beschreibung",
+      "meetingDescriptionPlaceholder": "Beschreibung des Meetings (optional)",
       "meetingStartLabel": "Start Datum & Uhrzeit",
       "meetingEndLabel": "Ende Datum & Uhrzeit",
       "meetingOrganizerLabel": "Organisator E-Mail",
@@ -240,7 +244,9 @@
     "creator": {
       "title": "Créer une nouvelle réunion",
       "meetingNameLabel": "Nom de la réunion",
+      "meetingNamePlaceholder": "Ma réunion",
       "meetingDescriptionLabel": "Description",
+      "meetingDescriptionPlaceholder": "Description de la réunion (facultatif)",
       "meetingStartLabel": "Date et heure de début",
       "meetingEndLabel": "Date et heure de fin",
       "meetingOrganizerLabel": "Email de l'organisateur",
@@ -328,7 +334,9 @@
     "creator": {
       "title": "创建新会议",
       "meetingNameLabel": "会议名称",
+      "meetingNamePlaceholder": "我的会议",
       "meetingDescriptionLabel": "描述",
+      "meetingDescriptionPlaceholder": "会议描述（可选）",
       "meetingStartLabel": "开始日期和时间",
       "meetingEndLabel": "结束日期和时间",
       "meetingOrganizerLabel": "组织者邮箱",