Add zh_CN language translation

[david921518]

All Submissions:

• [*] Have you followed the Contributing guideline?
• [*] Does your code follow the WordPress' coding standards?
• [*] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

This PR add the Simple Chinese support of zh_CN translation.

How to test the changes in this Pull Request:

1. Add the .po and .mo files into languages/ directory;
2. Select the system languange to zh_CN;
3. Refresh the web page to check if it shows the Simple Chinese

Other information:

• [*] Have you added an explanation of what your changes do and why you'd like us to include them?
• [*] Have you successfully run tests with your changes locally?

Changelog entry

Add zh_CN Simple Chinese language translation.

[dparker1005]

Hi @david921518

Thank you for contributing these translation files. To include translations in Paid Memberships Pro, they must be submitted via GlotPress. You can find detailed instructions on how to submit translations in this article: How to Contribute a New Translation.

Once you’ve submitted the translations to GlotPress, we would be happy to compensate you for your effort. Please follow up with us via our Contact Form to arrange this.