Add interactive palindrome checker for words and sentences

[tm4rtin17]

Summary

This pull request adds a Python-based palindrome checker that allows users to:

• Check whether a single word is a palindrome
• Scan a sentence and identify all palindromic words

The program runs interactively in the terminal and supports repeated checks without restarting.

Changes

• Added word palindrome checking functionality
• Added sentence parsing and palindrome detection
• Implemented input validation using pyinputplus
• Added looping logic to allow multiple checks in one run

Testing

• Manually tested with palindromic and non-palindromic words
• Tested sentence input with punctuation and mixed case
• Verified user input validation and repeat prompts

Notes

This is a small standalone project intended for learning and practice.