readSvg = async (filepath, isZipped = false) => {
    if (isZipped) {
        const compressed = await fs.readFile(filepath);
        return (await gunzip(compressed)).toString();
    }

    return await fs.readFile(filepath, 'utf8');
}
@param {String} filepath
@param {Boolean} isZipped
@returns {Promise<String | null>}

Reads .svg or .svgz files and returns the content as a string.