Call DocToImages sample with necessary command line arguments

- The DocToImages sample was failing to run in CI because it requires
  some additional command line arguments. Let's add some logic to the
  "Run samples" step to run the DocToImages sample with th  appropriate
  arguments.

.github/workflows/test-net-framework-samples.yml

@@ -149,7 +149,11 @@ jobs:
               sample_name=$(basename "$PWD")
 
               if [ "$sample_name" != "PrintPDF" ] && [ "$sample_name" != "PrintPDFGUI" ] && [ "$sample_name" != "DisplayPDF" ] && [ "$sample_name" != "DotNETViewer" ] &&  [ "$sample_name" != "DotNETViewerComponent" ] &&  [ "$sample_name" != "PDFObjectExplorer" ]; then
-                bin/Release/$sample_name.exe
+                if [ "$sample_name" == "DocToImages" ]; then
+                  bin/Release/$sample_name.exe -format=png $HOME/.nuget/packages/adobe.pdf.library.sampleinput/1.0.0/build/Resources/Sample_Input/ducky.pdf
+                else
+                  bin/Release/$sample_name.exe
+                fi
               else
                 echo "$sample_name will not be run due to GitHub runner limitations."
               fi