[BUG] Rotating banner causes page height changes

[dtaivpp]

Describe the bug In blogs that have the rotating banner, the banner images are not a fixed height which causes the page to move around a lot.

To Reproduce Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior There should be a fixed height for the banner container and the images should be set to fit based off a fixed height and width. That way the page doesn't resize itself on every rotation.

[kolchfa-aws]

Maybe instead of a top-to-bottom transition we can have a left-to-right transition, which is more intuitive to the user. And I think it's best to get rid of the state where the header does not have any image but is just the markdown header.