spec: rename ocp to oci and add a link
spec: rename ocp to oci and add a link

Signed-off-by: Lai Jiangshan <b337eedf453972390e4695e362aeea2634ef4e0c@gmail.com>

zenlinTechnofreak/specs,hqhq/runtime-spec,kensipe/specs,laijs/specs,philips/specs,vbatts/specs,runcom/specs,vishh/specs,wking/opencontainer-runtime-spec,LK4D4/specs,cloudfoundry-incubator/specs,HardikDR/specs,wangkirin/specs,opencontainers/specs,opencontainers/runtime-spec,hqhq/specs,navidshaikh/specs,talwai/specs,wking/opencontainer-specs,ChengTiesheng/specs,dustymabe/specs,gao-feng/specs,marcosnils/specs,jonboulle/specs,ujuc/specs,mheon/specs