docs: add invalid placeholder case to demo

Author: navix

projects/ngxe/src/demo.json

@@ -40,6 +40,7 @@
       "3113514821997462868": "Additional options",
       "3179148736830644140": "Date of birth",
       "3291151548898871401": "{$TAG_INPUT} I need help booking my flight",
+      "3291151548898871402": "{$TAG_INPUT} I will book ticket myself",
       "3357031660050032232": "Thank you!",
       "3825802286872185103": "Calendar",
       "3971100408152984961": "Next",
@@ -78,6 +79,7 @@
         "3113514821997462868": "Additional options",
         "3179148736830644140": "Date of birth",
         "3291151548898871401": "{$TAG_INPUT} I need help booking my flight",
+        "3291151548898871402": "{$TAG_INPUT} I will book ticket myself",
         "3357031660050032232": "Thank you!",
         "3825802286872185103": "Show Calendar",
         "3971100408152984961": "Next",
@@ -119,6 +121,7 @@
           "3113514821997462868": "Zusatzoptionen",
           "3179148736830644140": "Geburtsdatum",
           "3291151548898871401": "{$TAG_INPUT} Ich brauche Hilfe bei der Buchung meines Fluges",
+          "3291151548898871402": "{$TAG_INPUT_INVALID} Ich werde das Ticket selbst buchen",
           "3357031660050032232": "Danke!",
           "3825802286872185103": "Kalender anzeigen",
           "3971100408152984961": "Nächster",
@@ -159,6 +162,7 @@
           "3113514821997462868": "Додаткові опції",
           "3179148736830644140": "Дата народження",
           "3291151548898871401": "{$TAG_INPUT} Мені потрібна допомога у придбанні основного перельоту",
+          "3291151548898871402": "{$TAG_INPUT_INVALID} Я сам забронюю квиток",
           "3357031660050032232": "Дякуємо!",
           "3825802286872185103": "Календар",
           "3971100408152984961": "Продовжити",