docs: Add a basic example for query (#12)

Author: yottahmd

README.md

@@ -15,8 +15,12 @@ Dew streamlines Go application development by providing a unified interface for
 - [Motivation](#motivation)
 - [Terminology](#terminology)
 - [Convention for Actions and Queries](#convention-for-actions-and-queries)
+  - [Example for `Action`:](#example-for-action)
+  - [Example for `Query`:](#example-for-query)
 - [Installation](#installation)
 - [Example](#example)
+  - [Hello Action Example](#hello-action-example)
+  - [Hello Query Example](#hello-query-example)
 - [Usage](#usage)
   - [Setting Up the Bus](#setting-up-the-bus)
   - [Dispatching Actions](#dispatching-actions)
@@ -55,14 +59,14 @@ graph LR
         Middleware
     end
 
-    Client -->|1. Dispatch Action| Bus
-    Client -->|2. Execute Query| Bus
-    Bus -->|3. Apply| Middleware
-    Middleware -->|4a. Route Action| ActionHandler
-    Middleware -->|4b. Route Query| QueryHandler
-    ActionHandler -->|5a. Handle & Modify State| DB[(Database)]
-    QueryHandler -->|5b. Fetch Data| DB
-    ActionHandler & QueryHandler -->|6. Return Result| Client
+    Client -->|1. Dispatch Action| Bus
+    Client -->|2. Execute Query| Bus
+    Bus -->|3. Apply| Middleware
+    Middleware -->|4a. Route Action| ActionHandler
+    Middleware -->|4b. Route Query| QueryHandler
+    ActionHandler -->|5a. Handle & Modify State| DB[(Database)]
+    QueryHandler -->|5b. Fetch Data| DB
+    ActionHandler & QueryHandler -->|6. Return Result| Client
 
     style Dew fill:#e6f3ff,stroke:#333,stroke-width:2px,color:#000
     style Bus fill:#b3e0ff,stroke:#333,stroke-width:2px,color:#000
@@ -95,7 +99,7 @@ Dew follows these conventions for `Action` and `Query` interfaces:
 - **Action Interface**: Each action must implement a `Validate` method to ensure the action's data is valid before processing.
 - **Query Interface**: Each query implements the `Query` interface, which is an empty interface. Queries don't require a `Validate` method as they don't modify application state.
 
-Example:
+### Example for `Action`:
 
 ```go
 // MyAction represents an Action
@@ -111,6 +115,12 @@ func (a *MyAction) Validate(ctx context.Context) error {
     return nil
 }
 
+```
+
+### Example for `Query`:
+
+```go
+
 // MyQuery represents a Query
 type MyQuery struct {
     AccountID string
@@ -129,7 +139,7 @@ go get github.com/go-dew/dew
 
 See [examples](examples) for more detailed examples.
 
-Basic usage:
+### Hello Action Example
 
 ```go
 package main
@@ -179,6 +189,53 @@ func (h *HelloHandler) HandleHelloAction(ctx context.Context, cmd *HelloAction)
 }
 ```
 
+### Hello Query Example
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "github.com/go-dew/dew"
+)
+
+// HelloQuery is a simple query that returns a greeting message.
+type HelloQuery struct {
+    // Name is the name of the user.
+    Name string
+
+    // Result is the output of the query.
+    // You can define any struct as the result.
+    Result string
+}
+
+func main() {
+    // Initialize the Command Bus.
+    bus := dew.New()
+
+    // Register the handler for the HelloAction.
+    bus.Register(new(HelloHandler))
+
+    // Create a context with the bus.
+    ctx := dew.NewContext(context.Background(), bus)
+
+    // Execute the query.
+    query, err := dew.Query(ctx, &HelloQuery{Name: "Dew"})
+    if err != nil {
+        fmt.Println("Error:", err)
+    } else {
+        fmt.Printf("Result: %+v\n", query.Result)
+    }
+}
+
+type HelloHandler struct {}
+func (h *HelloHandler) HandleHelloQuery(ctx context.Context, cmd *HelloQuery) error {
+    cmd.Result = fmt.Sprintf("Hello, %s!", cmd.Name)
+    return nil
+}
+```
+
 ## Usage
 
 ### Setting Up the Bus