Created by: shanyi15

After the website enhancement, there will be an API main-page.

We have to add an introduction on this page to tell users, for example, the features of PaddlePaddle API, and help them have a better grasp of our API documentation. The introduction may be from design doc, etc.

Thank you very much!

Project Background Optimize documentation of PaddlePaddle, enhancing user experience -----Optimization Plan: Stage 1 MRD -----Optimization Schedule（Update everyday）