Fixed POD in PDP_calculation_explanation.pod

Fixed POD in PDP_calculation_explanation.pod

podchecker PDP_calculation_explanation.pod showed:

*** WARNING: line containing nothing but whitespace in paragraph at line 46 in file PDP_calculation_explanation.pod
*** ERROR: Apparent command =head1 not preceded by blank line at line 176 in file PDP_calculation_explanation.pod
*** WARNING: node 'https://gallery.technet.microsoft.com/scriptcenter/Sample-Script-to-Generate-59c80d4c =head1 AUTHOR' contains non-escaped | or / at line 175 in file PDP_calculation_explanation.pod
*** ERROR: unresolved internal link 'https://gallery.technet.microsoft.com/scriptcenter/Sample-Script-to-Generate-59c80d4c =head1 AUTHOR' at line 175 in file PDP_calculation_explanation.pod
PDP_calculation_explanation.pod has 2 pod syntax errors.