upload_pdf_files does not check for file type or format #12
Description
Experimenting with notebooks can create .ipynb_checkpoints folder in RetrievalAugmentedGeneration/notebooks/dataset.
This will cause upload_pdf_files function to fail when increasing NUM_DOCS_TO_UPLOAD. The issue does not occur with default NUM_DOCS_TO_UPLOAD (100), as the number of .pdf files in dataset.zip is greater than 100.
