placement extensible scheduling proposal (#33)

* placement extensible scheduling proposal

Signed-off-by: haoqing0110 <[email protected]>

* update the proposal

Signed-off-by: haoqing0110 <[email protected]>

* update how prioritizer rate the clusters part

Signed-off-by: haoqing0110 <[email protected]>

* fix scalar typo

Signed-off-by: haoqing0110 <[email protected]>

* change the scope and CRD name

Signed-off-by: haoqing0110 <[email protected]>

* update the placement API and how to maintain the CRs

Signed-off-by: haoqing0110 <[email protected]>

* update negative weight use case and how to handle invalid scores

Signed-off-by: haoqing0110 <[email protected]>

* add description abouht negative weight

Signed-off-by: haoqing0110 <[email protected]>

* update status

Signed-off-by: haoqing0110 <[email protected]>