feat: add architecture overview

src/architecture/overview.md

@@ -5,4 +5,54 @@ Here, we describe PixeLAW's architecture.
 We built core layer. Builders can create their own application by interacting with core layer.
 ![overview](../images/overview.jpg)
 
-## Core Components
+## Core Layer
+To understand core layer, we delve into components and systems for that.
+
+### Core Components
+Here are the components.
+
+#### For System Properties
+- `x`: u64
+- `y`: u64
+- `created_at`: u64
+- `updated_at`: u64
+
+#### For User-changeable Properties
+- `app`: ContractAddress
+- `color`: u32
+- `owener`: ContractAddress
+- `text`: felt252
+- `timestamp`: u64
+- `action`: felt252
+
+![Components](../images/CoreComponents.jpg)
+
+
+### Core Systems
+These systems interact with core components.
+- `init`: Initialize the PixeLAW action model 
+- `update_permissions`: Grant permissions to a system by the caller
+- `update_app`: Updates the name of an app in the registry
+- `has_write_access`: Check the access for writing
+- `shedule_queue`: Shedule the process for queue
+- `process_queue`: Execute the process in queue
+- `update_pixel`: Update pixel information
+- `get_player_address`: Get the address
+- `get_system_address`: Get the address
+- `new_app`: Register an app
+
+## Applications on PixeLAW
+There are already some applications top of core layer for example.
+
+### Paint pixel
+By utilizing core systems, we can create our own pixel art game.
+![Paint](../images/PaintSystems.jpg)
+
+### Sanke Game
+For snake game, the queue system is important.
+![Snake](../images/SnakeSystems.jpg)
+
+
+## Queue System
+We use queue system to execute stacked processes.
+![Queue](../images/queue.jpg)