Facebook will confirm its commitment to add 500 skilled jobs to its London workforce today as part of a plan to expand its British headquarters from 4,000 to 7,000 employees within the next four years. This joins Google’s £1 billion investment in Britain, and Apple’s huge new HQ at Battersea as evidence that the tech sector is still thriving. Unemployment is falling and retail is surging, despite Brexit! Strangely, Google, Apple and Facebook are not worried about being outside the EU’s Digital Single Market, the over-regulated, over-subsidised irrelevance to the future…