Update PDF Merger and Splitter.py

[Sharmeen20]

Refactor PDF utility script with improved structure and error handling

• Added docstrings for merge_pdfs and split_pdf functions
• Improved filename handling using os.path.splitext
• Implemented error handling for file read/write operations
• Added user feedback via print statements
• Used enumerate with start=1 for better page numbering
• Prepared script for CLI usage with main block

PR Title

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Summary

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Description

The changes are as follows:

• Change 1
• Change 2

Checks

in the repository

• [x] Made no changes that degrades the functioning of the repository
• [x] Gave each commit a better title (unlike updated README.md)

in the PR

• [x] Followed the format of the pull_request_template
• [x] Made the Pull Request in a small level (for the creator's wellfare)
• [x] Tested the changes you made

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[Your Name]