Updated type sizes

JsonGenerator/README.md

@@ -163,5 +163,5 @@ This table is for an 8-bit Arduino, types would be bigger on a 32-bit processor.
 
 | Type                   | Size in bytes |
 | ---------------------- | ------------- |
-| JsonArray<N>     | 4 + 12 x N    |
-| JsonHashTable<N> | 4 + 14 x N    |
+| JsonArray<N>     | 4 + 6 x N     |
+| JsonHashTable<N> | 4 + 8 x N     |