DOC: Examples added for float_format in to_csv documentation
Closes #60363 

@rhshadrach Please check if the examples are appropriate. @mroeschke The reviewed changes are corrected, have a check and let me know if further changes are required. @mroeschke The code is changed accordingly to the reviewed changes, don't know why the tests are failing, can you please help me with it? Thanks @Uvi-12  @mroeschke Thank you for the reviews, that helped a lot.