Update BoAT_User_Guide_en.md
the description of "Figure 2-2 BoAT Architecture"
@@ -67,12 +67,17 @@ Smart contract call (manual construction)
![BoAT Architecture](/images/BoAT_User_Guide_en-F2-2-BoAT_architecture.png)
Figure 2-2 BoAT Architecture
-The Wallet API is an interface that the SDK provides to the IoT Application to call, including the SDK public interface and wallet and transaction interfaces for different blockchain protocols.
-The blockchain client interface protocol mainly implements transaction interface protocols for different blockchains, and interacts with blockchain nodes through the RPC interface.
-The remote procedure call(RPC) interface implements a warpper for different communication protocols. This component needs to be ported according to the specific communication method supported by the IoT device.
-Public components implement common functions such as RLP encoding, JSON codec, string processing, etc.
-Hardware dependent components are ported components involving different hardware, such as cryptography accelerators, secure storage, random numbers, etc. This component needs to be ported according to specific hardware. SDK also provides a set of default Hardware dependent components witch implementations by software.
-The tool component provides a set of Python tools, which are used to generate C language contract call interface of smart contract ABI interface based on Solidity or WASM C++.
+* The *Wallet API* is an interface that the SDK provides to the IoT Application to call, including the SDK public interface and wallet and transaction interfaces for different blockchain protocols.
+
+* The *Blockchain Client Interface Protocol* mainly implements transaction interface protocols for different blockchains, and interacts with blockchain nodes through the RPC interface.
+
+* The *Remote Procedure Call(RPC) interface* implements a warpper for different communication protocols. This component needs to be ported according to the specific communication method supported by the IoT device.
+
+* *Public Components* implement common functions such as RLP encoding, JSON codec, string processing, etc.
+
+* *Hardware Dependent Components* are ported components involving different hardware, such as cryptography accelerators, secure storage, random numbers, etc. This component needs to be ported according to specific hardware. SDK also provides a set of default Hardware dependent components witch implementations by software.
+
+* The *Tool Component* provides a set of Python tools, which are used to generate C language contract call interface of smart contract ABI interface based on Solidity or WASM C++.
