Minor doc update for DataOut with curved cells.
Minor doc update for DataOut with curved cells.

danshapero/dealii,spco/dealii,naliboff/dealii,naliboff/dealii,spco/dealii,jperryhouts/dealii,shakirbsm/dealii,naliboff/dealii,kalj/dealii,shakirbsm/dealii,pesser/dealii,angelrca/dealii,pesser/dealii,angelrca/dealii,sairajat/dealii,spco/dealii,angelrca/dealii,EGP-CIG-REU/dealii,EGP-CIG-REU/dealii,sairajat/dealii,naliboff/dealii,sairajat/dealii,shakirbsm/dealii,pesser/dealii,angelrca/dealii,angelrca/dealii,shakirbsm/dealii,EGP-CIG-REU/dealii,JaeryunYim/dealii,kalj/dealii,danshapero/dealii,pesser/dealii,angelrca/dealii,EGP-CIG-REU/dealii,JaeryunYim/dealii,EGP-CIG-REU/dealii,shakirbsm/dealii,spco/dealii,danshapero/dealii,danshapero/dealii,shakirbsm/dealii,jperryhouts/dealii,kalj/dealii,sairajat/dealii,naliboff/dealii,kalj/dealii,JaeryunYim/dealii,JaeryunYim/dealii,EGP-CIG-REU/dealii,spco/dealii,jperryhouts/dealii,sairajat/dealii,JaeryunYim/dealii,jperryhouts/dealii,danshapero/dealii,naliboff/dealii,JaeryunYim/dealii,jperryhouts/dealii,jperryhouts/dealii,kalj/dealii,jperryhouts/dealii,pesser/dealii,spco/dealii,pesser/dealii,pesser/dealii,danshapero/dealii,kalj/dealii,EGP-CIG-REU/dealii,sairajat/dealii,sairajat/dealii,spco/dealii,JaeryunYim/dealii,naliboff/dealii,danshapero/dealii,angelrca/dealii,kalj/dealii,shakirbsm/dealii