functions.xml Eliminate confusion in fn's parameters and arguments

[mmalferov]

If we agree that a) parameters are part of the function signature, i.e. an integral part of the function declaration, and b) arguments are information that comes to the function from the outside, then we must eliminate confusion in the text. To simplify it: the arguments are passed, and the parameters take values from the arguments and, after argument's expression are evaluated, set values for their parameters. If so, there seem to be inconsistent places in the text where parameters are passed and functions take parameters rather than arguments or something like that

[Girgias]

This whole section needs a rewrite and reorganisation as how we talk about functions currently is clunky AF.

[mmalferov]

If the current proposal does not contain errors, can we at least accept them and make global changes later? I have already made changes to the Russian version and received criticism from colleagues for the fact that the translation text deviates from the original. But I can't leave the literal translation either, because the current original confuses the reader by calling arguments parameters and vice versa. I would like the function parameters to remain parameters, and the arguments that the function receives from the outside to remain arguments.