Features.yml: add screenshots

Merged username-removed-236961 requested to merge features-add-screenshots-1 into master

Add screenshots to features in features.yml.

Closes https://gitlab.com/gitlab-com/www-gitlab-com/issues/1605

Artboards w 1235 px x h 822.85 px

Notes:

Edited by 🚄 Job van der Voort 🚀