Added new articles and videos

[conejoninja]

I could not test this change (but it's trivial enough) because the theme docsy is outdated and I couldn't downgrade my version of hugo.

There's a PR to update docsy ( #466 ), but we should check the deployment version of hugo too.

Note: It's been a while, should I merge against release or dev ?

[deadprogram]

Note: It's been a while, should I merge against release or dev ?

I usually merge to dev and then manually merge to release when ready.

[conejoninja]

Changed the base branch

[deadprogram]

Thanks @conejoninja now merging.