Updates example, README, and build.zig.zon

[emmettmcdow]

Went to go use the example for the first time, and ran into a couple issues. These changes got it working on my machine for Zig 0.14.0.

I also updated the README.md to reflect these changes.

[raugl]

Thank you for showing interest in my project, but may I ask why? I will look into the issues you discovered and probably update the bindings to be inline with zig-0.16, but past that this project is basically abandoned.

On the official clay repo, they endorse two other zig bindings that are more maintained:

• https://github.com/johan0A/clay-zig-bindings (more frequent updates)
• https://codeberg.org/Zettexe/clay-zig (I personally like this one's API more)

At one point mine were the most complete bindings, but I decided it was easier to just build my own layout engine directly in zig based on Nic's tutorial than maintain this.