docs:perfect 128-bit UUID description

The previous description is not easy for the reader to understand, some changees have been made to perfect it.
Closes https://github.com/espressif/esp-idf/issues/5057

examples/bluetooth/bluedroid/ble/gatt_client/tutorial/Gatt_Client_Example_Walkthrough.md

@@ -484,7 +484,8 @@ Where,
 ```c
 #define REMOTE_SERVICE_UUID        0x00FF
 ```
-There will be a detail to note if the UUID of the service application that the client is interested in is a 128-bit UUID, which is related to the little-endian storage mode of the processor architecture . The struct of UUID is defined as:
+If UUID of the service application the user is interested in is 128-bit, then there is one note below for the user which is relevant with the little-endian storage mode of the processor architecture. 
+The struct of UUID is defined as:
 
 ```c
 typedef struct {
@@ -500,7 +501,7 @@ typedef struct {
 } __attribute__((packed)) esp_bt_uuid_t;
 ```
 
-In little-endian storage mode, you can define service UUID directly in the normal order if it's a 16-bit or a 32-bit UUID. However, if service UUID is a 128-bit UUID, there is a little difference. For example, if the UUID of the service application that the client is interested in is 12345678-a1b2-c3d4-e5f6-9fafd205e457, `REMOTE_SERVICE_UUID` should be defined as {0x57,0xE4,0x05,0xD2,0xAF,0x9F,0xF6,0xE5,0xD4,0xC3,0xB2,0xA1,0x78,0x56,0x34,0x12}.
+Note: In little-endian storage mode, you can define service UUID directly in the normal order if it's a 16-bit or a 32-bit UUID, but if service UUID is 128-bit, there is minor difference. For example, if the UUID of the service application that the user is interested in is 12345678-a1b2-c3d4-e5f6-9fafd205e457, `REMOTE_SERVICE_UUID` should be defined as {0x57,0xE4,0x05,0xD2,0xAF,0x9F,0xF6,0xE5,0xD4,0xC3,0xB2,0xA1,0x78,0x56,0x34,0x12}.
 
 The services are then discovered as follows: