add chapters

books/architecture/src/SUMMARY.md

@@ -28,7 +28,32 @@
 ---
 
 - [⚪️ Storage](storage/intro.md)
-    - [⚪️ Database abstraction](storage/database-abstraction.md)
+    - [⚪️ Database abstraction](storage/db/intro.md)
+        - [⚪️ Backends](storage/db/backends/intro.md)
+        - [⚪️ Layers](storage/db/layers/intro.md)
+            - [⚪️ Backend](storage/db/layers/backend.md)
+            - [⚪️ ConcreteEnv](storage/db/layers/concrete_env.md)
+            - [⚪️ Trait](storage/db/layers/trait.md)
+            - [⚪️ `ops`](storage/db/layers/ops.md)
+            - [⚪️ Service](storage/db/layers/service.md)
+        - [⚪️ The service](storage/db/service/intro.md)
+            - [⚪️ Initialization](storage/db/service/initialization.md)
+            - [⚪️ Requests](storage/db/service/requests.md)
+            - [⚪️ Responses](storage/db/service/responses.md)
+            - [⚪️ Thread model](storage/db/service/thread-model.md)
+            - [⚪️ Shutdown](storage/db/service/shutdown.md)
+        - [⚪️ Syncing](storage/db/syncing.md)
+        - [⚪️ Resizing](storage/db/resizing.md)
+        - [⚪️ (De)serialization](storage/db/serde.md)
+        - [⚪️ Schema](storage/db/schema/intro.md)
+            - [⚪️ Tables](storage/db/schema/tables.md)
+            - [⚪️ Multimap tables](storage/db/schema/multimap.md)
+        - [⚪️ Known issues and tradeoffs](storage/db/issues/intro.md)
+            - [⚪️ Traits abstracting backends](storage/db/issues/traits.md)
+            - [⚪️ Hot-swappable backends](storage/db/issues/hot-swap.md)
+            - [⚪️ Copying unaligned bytes](storage/db/issues/copy.md)
+            - [⚪️ Endianness](storage/db/issues/endian.md)
+            - [⚪️ Extra table data](storage/db/issues/extra-table-data.md)
     - [⚪️ Blockchain](storage/blockchain.md)
     - [⚪️ Transaction pool](storage/transaction-pool.md)
     - [⚪️ Pruning](storage/pruning.md)