Function blockish::render_thread_pool

pub fn render_thread_pool(
    width: u32, 
    height: u32, 
    coordinate_to_rgb: &(dyn Fn(u32, u32) -> (u8, u8, u8) + Sync + Send), 
    write_eol: bool, 
    pool: &mut Pool, 
    output_buffers: &mut Vec<Vec<u8>>
)