Simple Convert RGB color to hexadecimal color
```toml [dependencies] rgb2hex = "0.1.0" ````
```rs use rgb2hex::{rgb2hex::*, RGB};
assert_eq!( new(RGB { r: 251, g: 169, b: 12 }), Ok(0xfba90c) ); // RGB -> Hex
asserteq!(newfrom_str("251 ,169,12"), Ok(0xfba90c)); // RGB (string) -> Hex
asserteq!(newfrom_arr(vec![251, 169, 12]), Ok(0xfba90c)); // RGB (array) -> Hex ```