add bench tests

[softprops]

unlike rust and go, zig has no out of the box benchmark testing built in but there are a handful of libraries that could fill the gap. to better understand the footprint json logging is expected to add a baseline benchmark that compares std.log.info with and without json logging would be helpful.

let's research the libraries available, pick one and add that benchmark test

we'd like something that's

• simple to use
• installable with zigs native package manager
• compatible with release versions of zig

[softprops]

here are a few that popped in a quick google search

https://github.com/Hejsil/zig-bench
https://github.com/Sahnvour/zig-benchmark