Fix transition in title_image.html

The transition in the title image include misses the direction parameter.

https://gitlab.hzdr.de/hifis/software.hifis.net/-/blob/8c4f6204f301b96e5228558b2e25b1c064f3f1cd/_includes/title_image.html#L43

At least on experiments with hifis.net it also shows possibly incorrect behavior regarding to its positioning.