Adding i18n translations

[zhongnansu]

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Hi,
From what I see in the code most strings are hardcoded in english. Is there any ongoing work to add i18n translation support to this plugin?
If I were to do this myself, completely or partially (ie. just critical user-facing parts), can I submit a pull request? Aside from general contribution guidelines, is there anything I should be aware of when trying to implement that?

**This issue is submitted by @starcatter **
opendistro-for-elasticsearch/kibana-reports#348