Commander.js: Update Chinese README for 7.0

[shadowspawn]

A PR to update the Chinese version of README is welcome.

README commits on release/7.x:
https://github.com/tj/commander.js/commits/release/7.x/Readme.md

Compare between master and release/7.x:
https://github.com/tj/commander.js/compare/master...release/7.x

Quite a few changes to the README with some rearrangements, some additions, and catching up with latest code patterns.

There is some new additional documentation in the docs folder, but I think those files are less important than the README:
https://github.com/tj/commander.js/tree/release/7.x/docs

[CoderYihaoWang]

I can do both updating and translate docs folder = )

[shadowspawn]

Thanks @CoderYihaoWang

[shadowspawn]

A small heads-up, I am planning to change a few sentences in the README as part of #1429 soon.

[CoderYihaoWang]

Got it. Then I will send the PR after the #1429 one gets merged, to reflect the changes in the translation.

[shadowspawn]

Merged #1429

[CoderYihaoWang]

I have completed the translation and submitted PR = )

[shadowspawn]

Included in Commander 7.0.0.