docs: add request diagram to @ganache/core

src/packages/core/ARCHITECTURE.md

@@ -0,0 +1,35 @@
+### Request Flow Sequence Diagram
+
+<!-- NOTE: if you change this diagram, change the UML as well -->
+
+![Request Flow Sequence Diagram](https://www.planttext.com/api/plantuml/svg/VPB1RiCW38RlUGhKUzJxD4sfgXrsg_O65bWDKceoSDezVar825HjJo3__uVD3rrWy3nTXcQKrMex0h7QTMSWq3tkjVEuKn3KKJPD-pMlwaDv_9imS0EQxHKOawwIFDk8KBFpufMJGzGAxo9ASK4-sxPYF8PfOD4DFiMUzUc1pF2sqUeLyEJTrHhqsrr-uJRRChrQvghQ2A6_wMmfve3_g2V6nPBHf2zLjTe5F9n-XBeWzyvaEMEYvcAcOZG9ar16Hs4xjmYdHFEa4SsZFj05MqsxfHJfAgQ2B-WgfbUFkP8ldZCHlXgpiihdwf2CVDGx)
+
+<!--
+@startuml
+participant "@ganache/core" as Core
+-> Core : request
+activate Core
+  Core -> Connector : parse
+  activate Connector
+    Core <-- Connector : result
+  deactivate Connector
+  Core -> Connector : handle
+  activate Connector
+    Connector -> Provider : requestRaw
+    activate Provider
+      Provider -> Engine : execute
+      activate Engine
+        Engine -> API : method
+        activate API
+          Engine <-- API : response
+        deactivate API
+        Provider <-- Engine : response
+      deactivate Engine
+      Connector <-- Provider : response
+    deactivate Provider
+    Core <-- Connector : response
+  deactivate Connector
+  <-- Core : response
+deactivate Core
+@enduml
+-->

src/packages/core/README.md

@@ -3,3 +3,7 @@
 The `ganache-core` npm package.
 
 See [README.md](../../../README.md) for info.
+
+### Architecture
+
+See [ARCHITECTURE.md](ARCHITECTURE.md)