add placeholders for remaining sections

Author: alimanfoo

slides/v3-update-20190619.md

@@ -190,3 +190,47 @@ document. Store.*
   case-insensitive name clashes).
 
 * I'm not happy with the spec's current approach to this.
+
+====
+
+### Core protocol - data types
+
+@@TODO
+
+====
+
+### Core protocol - chunk grids
+
+@@TODO
+
+====
+
+### Core protocol - chunk memory layouts
+
+@@TODO
+
+====
+
+### Core protocol - chunk encoding
+
+@@TODO
+
+====
+
+### Core protocol - metadata
+
+@@TODO bootstrap metadata; array metadata; group metadata; metadata
+encoding
+
+====
+
+### Core protocol - stores
+
+@@TODO store interface
+
+====
+
+### Core protocol - storage protocol
+
+@@TODO storage keys; protocol operations; group and array creation;
+implicit groups