0.5.0 Documentation https://ziglang.org/documentation/0.5.0/#Introduction
root std library https://github.com/ziglang/zig/tree/master/lib/std
examples of writing and reading to a file https://github.com/ziglang/zig/blob/master/lib/std/event/fs....
There are also a ton of projects that the creator has done with Zig, you can check those out for more examples as well.
https://github.com/andrewrk?utf8=%E2%9C%93&tab=repositories&...
Looks like he has an advent of code repo too.