How do I enable chinese input to Gboard keyboard? I already have Google Pinyin Input enabled, but when I try to add a keyboard to Gboard, Chinese doesn't show up. When I long click on the keyboard to switch languages, nothing else shows up either.
3/16/18 update - Chinese has been added to the supported languages in the latest version.
Original answer - Chinese is not supported in GBoard yet (as of 2/20). Neither are other East Asian languages such as Japanese and Korean. There's rumor that it'll be added in the upcoming versions.
For a full up-to-date list of languages supported, refer to this link - https://support.google.com/websearch/answer/6380730#languages