Improve content metadata field docs (#2620)
Improve content metadata field docs (#2620)

Improve content metadata field docs
getpelican/pelican,avaris/pelican,talha131/pelican,farseerfc/pelican,getpelican/pelican,iKevinY/pelican,ingwinlu/pelican,avaris/pelican,farseerfc/pelican,iKevinY/pelican,talha131/pelican,ingwinlu/pelican