Chinese e-commerce giant JD.com is ramping up its online grocery business and lower-tier market operations, as a slowing economy and draconian Covid-19 restrictions raise the urgency for the country’s largest private business to seek new growth engines. The Beijing-based firm announced on Tuesday that it aimed to bring more shoppers to its JD Supermarket service partly by strengthening partnerships with offline retailers, including Walmart. The US supermarket chain has been collaborating with the Chinese company to attract more online customers during the pandemic, with JD Supermarket contributing to roughly 40 per cent of sales at several Walmart outlets in Beijing,…