Look and Feel images and Export/Import section

I added the updated 6.2 images for the Look and Feel section but have a strong feeling they'll need to be updated. I'm waiting on confirmation through [LPS-38624](https://issues.liferay.com/browse/LPS-38624) or bundle updates, so I'll keep that ticket in progress and check on it periodically.

Also included Export/Import section, which should be good to go.

https://issues.liferay.com/browse/LRDOCS-591