Compile large icon files slowly

[nissy-dev]

The following files are nearly 30000 lines, so compile them slowly...

• io_icons.rs
• fa_solid_icons.rs
• bs_icons.rs
• fi_icons.rs

[nissy-dev]

I plan to divide it into each crate and provide each icon for each feature like web-sys.

web-sys's Cargo.roml: https://github.com/rustwasm/wasm-bindgen/blob/main/crates/web-sys/Cargo.toml