Persist authored Age generation plans (#31)

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -40,6 +40,7 @@
   "screen.rivencraft.book_binder.grammar.duplicate_panel": "Page %s: remove the extra Link Panel",
   "screen.rivencraft.book_binder.grammar.unresolved": "Page %s: missing symbol definition; restore its data pack or remove it",
   "screen.rivencraft.book_binder.grammar.unsupported": "Page %s: this symbol needs semantic schema v2; update its data pack or remove it",
+  "screen.rivencraft.book_binder.grammar.unsupported_profile": "Page %s: its Age profile is unavailable; restore the data pack or remove this page",
   "screen.rivencraft.book_binder.grammar.duplicate": "Page %s: remove the duplicate symbol",
   "screen.rivencraft.book_binder.grammar.conflict": "Page %s: replace the conflicting symbol",
   "screen.rivencraft.book_binder.grammar.out_of_order": "Page %s: move this symbol before later categories",