Editing head of marketing ad

Adding more detail to content - @anothertompetty thoughts?
Fleshing out Marketing ad

@anothertompetty shall we?
Merge pull request #345 from gocardless/edit-marketing-ad2

Editing head of marketing ad
Lose the team image
Fixing 'engineering interns' link

@jamesshedden not sure how I broke it.
Merge pull request #348 from gocardless/fixing-intern-link

Fixing 'engineering interns' link
Merge branch 'dev'