Fix typos in 01 Image Basics.
Fix typos in 01 Image Basics.

thewtex/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,zivy/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,thewtex/SimpleITK-Notebooks,zivy/SimpleITK-Notebooks,thewtex/SimpleITK-Notebooks,zivy/SimpleITK-Notebooks