message: [doc] A small change to README
  update --local-account-dir args to ~/.starcoin/main/account_vaults
diff: @@ -70,7 +70,7 @@ starcoin --connect ws://main.seed.starcoin.org:9870 console
  Connect to the main network seed nodes and use a local account database for using Account-related commands
  ```shell
  -starcoin --connect ws://main.seed.starcoin.org:9870 --local-account-dir ~/.starcoin/account_vaults console
  +starcoin --connect ws://main.seed.starcoin.org:9870 --local-account-dir ~/.starcoin/main/account_vaults console
  ```
  More detailed test network info please read [Join starcoin test network](https://developer.starcoin.org/en/setup/runnetwork/).
  