static fromFilePath(filePath) {
        const b64data = fs.readFileSync(filePath, {encoding: 'base64'});
        const mimetype = mime.getType(filePath); 
        const filename = path.basename(filePath);

        return new MessageMedia(mimetype, b64data, filename);
    }
Creates a MessageMedia instance from a local file path
@param {string} filePath 
@returns {MessageMedia}