Update public_bookcase.json

ToDo (optional):
- Decide whether to keep books=children;adults (possibly redundant; may mean the same as leaving it empty)
- Lock values `children`/`adults`(/`children;adults`) (combined choice + string question, like opening hours).

assets/layers/public_bookcase/public_bookcase.json

@@ -144,12 +144,23 @@
       "id": "bookcase-booktypes",
       "question": {
         "en": "What kind of books can be found in this public bookcase?",
-        "nl": "Voor welke doelgroep zijn de meeste boeken in dit boekenruilkastje?",
+        "nl": "Welke soort boeken zijn de meeste boeken in dit boekenruilkastje?",
         "de": "Welche Art von Büchern sind in diesem öffentlichen Bücherschrank zu finden?",
         "fr": "Quel type de livres peut-on dans cette microbibliothèque ?",
         "it": "Che tipo di libri si possono trovare in questa microbiblioteca?",
         "ru": "Какие книги можно найти в этом общественном книжном шкафу?",
         "hu": "Milyen fajta könyvek találhatók ezen a közösségi könyvespolcon?"
+      },
+            "render": {
+        "nl": "Deze plaats serveert vooral {books}",
+        "en": "This place mostly serves {books}",
+        "de": "An diesem Ort gibt es hauptsächlich {books}"
+      },
+      "freeform": {
+        "key": "books",
+        "addExtraTags": [
+          "fixme=Freeform tag `books` used, to be doublechecked"
+        ]
       },
       "mappings": [
         {