`.do` arguments not passed correctly

The current implementation of the callback chain in 5a-chain passes data from the previous callback but doesn't pass arguments explicitly mentioned in .do().

In usage example readConfig callback is expected to receive myConfig as an argument.

const startChain = chain()
  .do(readConfig, 'myConfig')
  .do(selectFromDb, 'select * from cities')
  .do(getHttpPage, 'http://kpi.ua')
  .do(readFile, 'README.md');

However it receives undefined instead.

So if callbacks would really depend on the previous one the chain would fail once it was called.

Also, should only the first callback in the chain receive an explicit argument, and the following ones receive their arguments from the previous one? Or should they receive both explicit and implicit arguments?

首先檢查 5a-chain 中的 callback 鏈實作，以及展示 readConfig、selectFromDb、getHttpPage 和 readFile 的使用範例。追蹤引數如何透過每次 .do() 呼叫傳遞，然後驗證文件中所述的 callback 是否接收到預期的明確引數和前一個 callback 的引數，而不是 undefined。