a11y: author names read out twice with screen reader for each post

[dstorey]

https://next.smashingmagazine.com/

steps:

Navigate to any of the article summaries or the articles themselves with screen reader and read out the author byline.

Expected:

Something like "Vitaly Friedman wrote"

Actual:

"Vitaly Friedman Vitaly Friedman wrote"

Reason:

author pictures are images with the same alt text as the text directly after it.

Fix:

Add alt="" instead.