update doc

README.md

@@ -263,8 +263,11 @@ const { smartpack, smartunpack, plikOneshotUpload, fetchWithBackoff } = msghandl
 // Data format: [[dataname, data, type], ...]
 const payload1 = ["test_message", "Hello World", "text"];
 const payload2 = ["config_data", { key: "value" }, "dictionary"];
+const payload3 = ["table_data", [{id: 1, name: "Alice"}], "jsontable"];
+const image_bytes = new Uint8Array([1, 2, 3, ...]); // Image data
+const payload4 = ["user_avatar", image_bytes, "image"];
 
-const payloads = [payload1, payload2];  // Array of arrays
+const payloads = [payload1, payload2, payload3, payload4];  // Array of arrays
 
 // Step 1: Create the message envelope (transport-agnostic)
 const [envelope, envelopeJsonStr] = await msghandlerCSR.smartpack("test.topic", payloads, {
@@ -463,7 +466,7 @@ env, env_json_str = smartpack("/device/config", data)
 
 ### Example 3: Table Data (Arrow IPC - Julia Only)
 
-Send tabular data using Apache Arrow IPC format.
+Send tabular data using Apache Arrow IPC format for efficient binary serialization:
 
 ```julia
 using msghandler
@@ -479,7 +482,25 @@ data = [("students", df, "arrowtable")]
 env, env_json_str = smartpack("/data/analysis", data)
 ```
 
-### Example 3b: Table Data (JSON - JavaScript Compatible)
+### Example 3b: Table Data (JSON - Julia Compatible)
+
+For cross-platform compatibility or when Arrow IPC is not needed, use `jsontable`:
+
+```julia
+using msghandler
+using DataFrames
+
+df = DataFrame(
+    id = [1, 2, 3],
+    name = ["Alice", "Bob", "Charlie"],
+    score = [95, 88, 92]
+)
+
+data = [("students", df, "jsontable")]
+env, env_json_str = smartpack("/data/analysis", data)
+```
+
+### Example 3c: Table Data (JSON - JavaScript Compatible)
 
 For JavaScript frontend, use `jsontable` instead of `arrowtable`:
 
@@ -495,7 +516,34 @@ const [envelope, envelopeJsonStr] = await msghandlerCSR.smartpack("/data/analysi
 ]);
 ```
 
-### Example 4: Request-Response Pattern
+### Example 4: Image Transmission (Julia)
+
+Send image data directly in messages:
+
+```julia
+using msghandler
+
+# Read image file
+image_path = "./path/to/image.jpg"
+image_data = read(image_path)
+
+data = [("user_avatar", image_data, "image")]
+env, env_json_str = smartpack("/chat/room1", data; fileserver_url="http://localhost:8080")
+```
+
+### Example 5: Image Transmission (JavaScript)
+
+Send image data directly in messages:
+
+```javascript
+const image_data = new Uint8Array([1, 2, 3, ...]); // Image bytes
+
+const [envelope, envelopeJsonStr] = await msghandlerCSR.smartpack("/chat/room1", [
+    ["user_avatar", image_data, "image"]
+]);
+```
+
+### Example 6: Request-Response Pattern
 
 Bi-directional communication with reply-to support.