GRAMMAR: {
    readonly A: {
        readonly type: "image/avif";
        readonly ext: readonly ["avif"];
    };
    readonly G: {
        readonly type: "image/gif";
        readonly ext: readonly ["gif"];
    };
    readonly J: {
        readonly type: "image/jpeg";
        readonly ext: readonly ["jpeg", "jpg"];
    };
    readonly P: {
        readonly type: "image/png";
        readonly ext: readonly ["png"];
    };
    readonly T: {
        readonly type: "image/tiff";
        readonly ext: readonly ["tiff", "tif"];
    };
    readonly W: {
        readonly type: "image/webp";
        readonly ext: readonly ["webp"];
    };
}