book: added layers to architecture overview

doc/src/SUMMARY.md

@@ -5,6 +5,7 @@
 - [Development](development.md)
 - [Architecture](architecture/architecture.md)
   - [Overview](architecture/overview.md)
+  - [Layers](architecture/layers.md)
   - [Anonymous Assets](architecture/anonymous_assets.md)
   - [Blockchain](architecture/blockchain.md)
   - [DNA](architecture/dna.md)

doc/src/architecture/layers.md

@@ -0,0 +1,17 @@
+# Layers
+
+* **system/** contains core functionality, types and utilities.
+* **net/** is the p2p networking base layer.
+* **service/** any services such as the cashier or gateways.
+* **zk/** is the zk virtual machine and related zk code.
+* **zkas/** is the zk assembly language and compiler.
+* **crypto/** for the merkle tree classes and other crypto primitives.
+* **node/** is a fully working darkfi node.
+* **wallet/** key generation and management features such as derivation and storage.
+* **tx/** for the transaction builder.
+* **blockchain/** blockchain database functionality and state transition.
+* **consensus/** implementation of the streamlet consensus algorithm.
+* **rpc/** interface for remote procedure calls, includes adapter to interface with the node backend and the default jsonrpc transport mechanism.
+* **util/** various utilities.
+
+

doc/src/architecture/overview.md

@@ -50,4 +50,3 @@ compile and inspect contracts.
 zkVM aims to be a general-purpose zkSNARK virtual machine that empowers
 developers to quickly prototype and debug zk contracts. It uses a
 trustless zero-knowledge proof system called Halo 2 with no trusted setup.
-