`std.fs.File.stdout()` is now `std.Io.File.stdout()`

[brendanny]

In zig v0.16.0, File has been moved from std.fs to std.Io.¹ Also, writer() now takes three arguments instead of two (implicit file, Io (new), and buffer)²

particularly important in chapter 1 (i've not gotten any further)

Footnotes

1. https://ziglang.org/documentation/master/std/#std.Io.File ↩

2. https://ziglang.org/documentation/master/std/#std.Io.File.writer ↩

[pedropark99]

(mental note) This is kind of a big change in the book, and therefore should be the priority.

[pedropark99]

Issue fixed with #223