Regression: Restore external links icons

Move content images to content folder

Fixes broken external link images, since the styles for those
were moved in Ife4b510c1663d6da5691bcc3714908810615aa40

Change-Id: I387d4c4ac9b180d59bf11a4bdb5cc9e487355a35
Merge "Regression: Restore external links icons"