Created by: gangliao

Improve the design doc of Docker build #1627

• remove book submodule from paddle repo @gangliao #1631
• add paddle submodule in book repo @gangliao https://github.com/PaddlePaddle/book/pull/218
• paddle dev dockerfile paddle:<version>-dev #1598 @typhoonzero
• paddle production image paddle:<version> via paddle dev #1598 @typhoonzero
• paddle book dockerfile @gongweibao https://github.com/PaddlePaddle/book/pull/220