Incorrect description of isWhitespace in website documentation

Documentation of `isWhitespace` function on [Arduino website](https://www.arduino.cc/reference/tr/language/functions/characters/iswhitespace/) says

> Analyse if a char is a white space, that is space, formfeed ('\f'), newline ('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab ('\v')).

This is not correct. Implementation of `isWhitespace` function in arduino core defines it as a synonym of C function `isblank`, which only matches space and \t

Open the linked Arduino Reference page for isWhitespace and compare its description with the behavior stated in the issue. Update the Turkish documentation so it describes matching space and horizontal tab only, then review the rendered page to confirm the corrected wording.

Written by the indexing model from the issue text.