feat: display both methods of manipulating the serial conn

readme.md

@@ -36,8 +36,14 @@ python3 -m pip install -U .
 from charachorder import CharaChorder
 
 for device in CharaChorder.list_devices():
+    # Method 1
     with device:
-        print(device.execute("ID"))
+        print(device.get_id())
+
+    # Method 2
+    device.open()
+    print(device.get_id())
+    device.close()
 ```
 
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