Add blank symbol and link-panel pages (#18)

README.md

@@ -11,6 +11,11 @@ and randomly seeded, persistent vanilla-like Ages created from page-free
 Descriptive Books. Instability and full symbol-to-world grammar interpretation
 have not been ported yet.
 
+Milestone 4 now includes stackable blank Pages plus server-created symbol,
+unresolved-symbol, and baseline link-panel states. Page visuals follow the
+legacy runtime-composition rules; written-page creation will become available
+through the Writing Desk work that follows.
+
 ## Linking Book
 
 Craft a Linking Book from a vanilla book and an ender pearl, then use it in the