First commit for PR, a little additions for the convenience of debugg…

[lprintf]

This is a simple PR whith a little additions, for familiaring the open source project contribution process and this project. Please point out any substandard points.

[CLAassistant]

All committers have signed the CLA.

[huan]

Hi, thanks for submitting your first PR to the repo!

I have invited you to the team of our Wechaty GitHub Org, please accept it by visit the below links in the message:

You've invited 肝之炼金师 to Wechaty! They'll be receiving an email shortly. They can also visit https://github.com/wechaty to accept the invitation.

For this PR, please follow the below requirements and make changes as needed:

1. create an Issue to describe what you need to do in detail, and then link all related PRs to the issue
2. split the mixed PR into different branches/PRs that one PR/branch only related to one problem/solution.
3. remove all unrelated changes in your PR, for example, your debug script.
4. keep the coding style/formatting as same as the original ones.