By Felix Onuah ABUJA (Reuters) – Shell Plc sees a $5 billion offshore oil investment opportunity in Nigeria and pledged to spend a further $1 billion in five to 10 years to boost natural gas output for domestic supplies and exports, a presidential spokesperson said on Thursday, citing Shell’s director of upstream operations. Nigerian President Bola Tinubu held talks with Shell’s Zoe Yujnovich in a move to attract capital to Africa’s top energy producer, presidential spokesperson Ajuri Ngelale said in a statement. Yujnovich was cited as saying Shell has “an imminent $5 billion investment opport…