Refactor __repr__ method in TinyDB class for clarity and consistency

[marcfreir]

This pull request improves the __repr__ method in the TinyDB class for better readability and maintainability by:

• Using f-strings instead of .format() for string interpolation.
• Keeping the functionality identical while improving clarity and modernizing the code style.
• Verified with tests to ensure no changes to functionality.

[msiemens]

Hey @marcfreir, thanks for your PR! I like rewriting the .format calls to f-strings. Could you just make sure you use single quotes ' instead of double quotes " like the rest of the code does (except for doc strings)?

[marcfreir]

Hey @marcfreir, thanks for your PR! I like rewriting the .format calls to f-strings. Could you just make sure you use single quotes ' instead of double quotes " like the rest of the code does (except for doc strings)?

Hi @msiemens, thanks for the feedback! I'll update the PR to use single quotes to maintain consistency with the project's code style. I'll push the changes shortly.