Fixed section typo
Signed-off-by: Virginia Adams <vadams@nvidia.com>

Fixed Bugs 3509889 and 3509839:

https://nvbugswb.nvidia.com/NVBugs5/redir.aspx?url=/3509889 [ML-NeMo][Tesla A30] Token_Classification-BioMegatron.ipynb contains a typo 

https://nvbugswb.nvidia.com/NVBugs5/redir.aspx?url=/3509839 [ML-NeMo][Tesla A30] Relation_Extraction-BioMegatron.ipynb contains a typo
