Simplified Chinese translation v1.0

[linhe0x0]

Ready for #38. The diagrams/images have not been translated yet, but we will finish these at the weekend. You can merge this one first. 😜

Translators: @XatMassacrE、@L9m 、@Airmacho、@xiaoyusilen、@jifaxu

[donnemartin]

Hi @sqrthree, @XatMassacrE, @L9m, @Airmacho, @xiaoyusilen, @jifaxu, awesome work!

I'm thinking of squashing this PR into a single commit on merge to keep the history clean, otherwise we'd have to do a fair amount of rebasing to clean up the commit messages to bring them more in line with the current commit message history.

Just as an example, a commit message like "Modify again" I think could provide more detail on what was changed. I wonder if we could also standardize commit messages to be English.

Of course the downside of squash is that the individual commits would be combined into one. We could add an AUTHORS.md or TRANSLATORS.md file with credits for each language and translators, although it looks like there is already translator info in the new translated README, nice!

What do you think?

[linhe0x0]

@donnemartin I have created a new branch to squash these commits. Now there's only one commit in the history. You can review it at #62.

[donnemartin]

Merged in #62, thank you!