feat!: update contract for 'Table.Get()'

doc_example_test.go

@@ -14,19 +14,19 @@ func Example_basic() {
 		fmt.Println("Put error:", err)
 	}
 
-	if item, err := table.Get(1); err != nil {
-		fmt.Println("Error:", err)
+	if item, ok := table.Get(1); !ok {
+		fmt.Println("Not Found 1!")
 	} else {
 		fmt.Println("Found 1:", item)
 	}
 
-	if item, err := table.Get(0); err != nil {
-		fmt.Println("Error:", err)
+	if item, ok := table.Get(0); !ok {
+		fmt.Println("Not Found 0!")
 	} else {
 		fmt.Println("Found 0:", item)
 	}
 
 	// Output:
 	// Found 1: Hello, World!
-	// Error: key '0' not found
+	// Not Found 0!
 }