Update migration.md

migration.md

@@ -11,19 +11,13 @@
 
 NOTE: you should always set `evmVersion` to `berlin`, Metis doesn't support `shanghai` hardfork yet.
 
-non-EIP155 txs is disabled for now
-
-you should always use EIP155 to build and sign your transactions.
-
-We will enable non-eip155 txs in next hardfork.
-
 2. Native token and wrapped
 
 Metis is a native token but also an ERC20 compatible token on Layer 2.
 
-It is a built-in feature, so there is no need to create a wrapped Metis token, and the source code is [here](https://github.com/MetisProtocol/mvm/blob/develop/packages/contracts/contracts/MVM/MVM_Coinbase.sol).
+The address is `0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000`, but we don't recommend using it, we will remove it in the future.
 
-Sushiswap team deployed a wMetis, it's the same with WETH9, and the contract address is [0x75cb093E4D61d2A2e65D8e0BBb01DE8d89b53481](https://andromeda-explorer.metis.io/address/0x75cb093E4D61d2A2e65D8e0BBb01DE8d89b53481/contracts)
+Sushiswap team deployed a wMetis, it's the same with WETH9, you can use it on your dapps, and the contract address is [0x75cb093E4D61d2A2e65D8e0BBb01DE8d89b53481](https://andromeda-explorer.metis.io/address/0x75cb093E4D61d2A2e65D8e0BBb01DE8d89b53481)
 
 ETH is an ERC20 token on Metis, its addresss is `0x420000000000000000000000000000000000000A`
 
@@ -39,8 +33,8 @@ It's the same with Ethereum.
 
 4. Block timestamp
 
-As said before. timestamp is not the same with current unix time, because Metis is an layer 2 chain, it depends on Ethereum layer 1 to get the timestamp.
+As said before. timestamp is not the same with current unix time, because Metis is a layer 2 chain, it depends on Ethereum layer 1 to get the timestamp.
 
-internally, Metis refreshes the timestamp once 1 minute for Andromeda. so you can see that many blocks have the same time on explorer or rpc.
+internally, Metis refreshes the timestamp once 10s for Andromeda. so you can see that many blocks have the same time on explorer or rpc.
 
-by the way, blocks are not generated at a constant time, a transaction will be confirmed immediately.
+by the way, blocks are generated per 2 seconds, but if there is no transactions, no blocks will be created.