message: docs: use permanent link for codes
diff: @@ -71,9 +71,7 @@ More information about Cell can be found in the [whitepaper](https://github.com/
  More information about Script can be [here](https://github.com/nervosnetwork/ckb-demo-ruby-sdk/blob/master/docs/how-to-write-contracts.md#script-model).
  -Also you can find how the `Script` structure is implemented from these codes:
  -
  -https://github.com/nervosnetwork/ckb/blob/17b48a0777753a91691146b3817758c02db6f415/core/src/script.rs#L13-L53
  +Also you can find how the `Script` structure is implemented from [these codes](https://github.com/nervosnetwork/ckb/blob/17b48a0777753a91691146b3817758c02db6f415/core/src/script.rs#L13-L53)
  