LONDON, March 16 : Chinese e‑commerce giant JD.com on Monday launched its Joybuy online marketplace in the UK, Germany, France, the Netherlands, Belgium and Luxembourg, stepping up its push beyond its home market and taking aim at market leader Amazon. JD.com wants to internationalise its business and last year agreed to buy German electronics retailer Ceconomy, owner of the MediaMarkt and Saturn brands, for 2.2 billion euros ($2.52 billion). The launch comes as Chinese retailers and brands