Signed-off-by: JoeyHwong <joeyhwong@gknow.cn>

Signed-off-by: llhuii <liulinghui@huawei.com>

1. add the design document of the basic framework.
2. add the roadmap.
3. add the proposal of joint inference.

Signed-off-by: Jie Pu <pujie2@huawei.com>