Add a EDL tutorial

[Yancey0623]

We need an EDL tutorial to introduce how to use EDL on a Kubernetes cluster.

[velconia]

Is this means that we should offer a paddle fluid demo on EDL?

[Yancey0623]

PaddlePaddle Fluid doesn't support full-tolerant and scaling yet, we can demo it by Paddle v2 and then switch to PaddlePaddle Fluid until Fluid EDL is ready, and I think Fluid and v2 have many common things and easy to the switch.