add Leptos

[gbj]

I don't think it's necessarily a good idea to add other languages, but I had put together a local implementation for comparison and @DylanPiercey asked to take a look. I do see #23 adding Dioxus as well, so I thought I'd just open this. Feel free to close if you want to keep it JS-specific.

There's no difference in the HTML rendered for this example for our with-hydration vs no-hydration versions except for very small script tag, so I just did no-hydration for the sake of simplicity in building/running it.

If you have a Rust toolchain installed this is just cargo run --release. I have it running on nightly Rust, it should work with stable if you just remove the nightly feature in Cargo.toml.

local autocannon results:

Running 10s test @ http://localhost:3000
10 connections


┌─────────┬──────┬──────┬───────┬──────┬─────────┬─────────┬───────┐
│ Stat    │ 2.5% │ 50%  │ 97.5% │ 99%  │ Avg     │ Stdev   │ Max   │
├─────────┼──────┼──────┼───────┼──────┼─────────┼─────────┼───────┤
│ Latency │ 1 ms │ 1 ms │ 3 ms  │ 5 ms │ 1.49 ms │ 0.87 ms │ 26 ms │
└─────────┴──────┴──────┴───────┴──────┴─────────┴─────────┴───────┘
┌───────────┬────────┬────────┬────────┬────────┬─────────┬─────────┬────────┐
│ Stat      │ 1%     │ 2.5%   │ 50%    │ 97.5%  │ Avg     │ Stdev   │ Min    │
├───────────┼────────┼────────┼────────┼────────┼─────────┼─────────┼────────┤
│ Req/Sec   │ 4,923  │ 4,923  │ 5,083  │ 5,175  │ 5,086.8 │ 72.97   │ 4,920  │
├───────────┼────────┼────────┼────────┼────────┼─────────┼─────────┼────────┤
│ Bytes/Sec │ 748 MB │ 748 MB │ 772 MB │ 786 MB │ 773 MB  │ 11.1 MB │ 748 MB │
└───────────┴────────┴────────┴────────┴────────┴─────────┴─────────┴────────┘

Req/Bytes counts sampled once per second.
# of samples: 10

51k requests in 10.01s, 7.73 GB read

(For the truly curious, I have a local version with a non-allocating version for the style that went up to 6k rps, but I thought it was a bit cheesy. This is the idiomatic version.)