pwg: rework scheduling docs
pwg: rework scheduling docs

mparis/gstreamer,cfoch/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,surround-io/gstreamer,mparis/gstreamer,centricular/gstreamer,jpakkane/gstreamer,shelsonjava/gstreamer,ensonic/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,jpakkane/gstreamer,mparis/gstreamer,Lachann/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,Lachann/gstreamer,cablelabs/gstreamer,collects/gstreamer,collects/gstreamer,krichter722/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,collects/gstreamer,jpxiong/gstreamer,centricular/gstreamer,krieger-od/gstreamer,jpxiong/gstreamer,collects/gstreamer,surround-io/gstreamer,mparis/gstreamer,collects/gstreamer,mparis/gstreamer,krieger-od/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,justinjoy/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,cfoch/gstreamer,cfoch/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer,justinjoy/gstreamer,cablelabs/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,cfoch/gstreamer,centricular/gstreamer,cfoch/gstreamer,lubosz/gstreamer,lovebug356/gstreamer,krichter722/gstreamer,lubosz/gstreamer,krichter722/gstreamer,Lachann/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,lovebug356/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,surround-io/gstreamer,surround-io/gstreamer,Lachann/gstreamer