Errors and Zig

The client library documentation is generated with a Zig script. The sample code is integration tested with a Zig script. So lots of things in Zig code need to handle failure. Now of course these potential failures would exist whether or not Zig exposed them. Ok so now that I'm fully bought into Zig errors there were still a few more things that tripped me up. While there's a dedicated effort around autodoc, the tool that builds docs for the standard library, I haven't yet stumbled on docs for contributing the main Zig docs. Then someone on the Zig Programming Language Discord pointed me at running zig build docs in the repo root to generate the HTML. And now I've got a PR up! We'll see what folks think.