Enhancement : Handled empty city selection with friendly placeholder and message (#17)

[kavanatn]

This PR fixes issue #17

✅ Changes made:

• Added a .gitignore file
• Updated app.py to handle empty city name inputs gracefully
• Minor code cleanup for better readability and stability

🖼️ Screenshots:

> When the input is empty, no city is shown. User is prompted to enter a valid city. > City names are displayed only after entering them in the search bar. > "City not found" message shown when the user enters an invalid city name. > Smooth and successful search experience with improved UX.

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Let me know if you'd like to add any feature tags or link to related issues!