Merge pull request darwinia-network#83 from darwinia-network/update_d…

…vm_intro

Note on precision diff between evm & runtime

docs/dvm/dvm-intro.md

@@ -5,6 +5,8 @@ sidebar_label: Introduction
 sidebar_position: 1
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-Darwinia Network has been working on the cross-chain area with the aim of interconnecting multiple chains, and Darwinia Network also wants to help existing blockchain applications migrate more easily between different networks.
+Darwinia Network has been focusing on the cross-chain technology with the aim of interconnecting multiple chains, and we hope to help existing blockchain applications migrate more smoothly between different networks.
 
-Darwinia Network provides smart contract solutions based on DVM(Darwinia Virtual Machine), which is compatible with the Ethereum virtual machine paradigm at the low level. Therefore, it is easy for projects in the Ethereum ecosystem to migrate to the Darwinia Network.
+Darwinia Network provides smart contract solutions based on DVM(Darwinia Virtual Machine), which is compatible with  **E**thereum **V**irtual **M**achine paradigm at the low level. Therefore, it is easy for projects in the Ethereum ecosystem to migrate to the Darwinia Network.
+
+> Note: Due to DVM, native tokens, CRAB, are implemented in two forms, ERC-20 and runtime. The most important difference between them is the decimal precision. The decimal precision of the ERC-20 version is 18, while the precison for the runtime version is 9.