Merge pull request #242 from wangdx/master

Update two of the Chinese translation docs.
Merge pull request #243 from wangdx/master

Improve Chinese docs of index and getting-started.
Create CONTRIBUTING.md

A link to this doc will be displayed at the top of the 'new issue' screen. Additions or corrections are welcome.
Corrected internal links.
Polishing zh translation, 'properties' section of Configuration.
Improve the zh-translation, 'settings' part of configuration.
Polishing the java doc.
Improve the zh-doc, 'typeAliases' section of configuration
Improve the zh-doc, 'typeHandlers' section of configuration