move apple design guidelines to the bottom

lectures/user-experience/slides.qmd

@@ -52,10 +52,13 @@ a user actually wants to have a product
 ## Colors {.leftalign}
 * use common color codes (e.g. <span style="color:green;">green = OK</span>, <span style="color:red;">red = Problem</span>)
 * be inclusive and dont't fully rely on colors
-* useful guidlines for further reading: [Apple Design Guidelines](https://developer.apple.com/design/human-interface-guidelines/color)
 
 ![Typical Labview inteface [NCAR docu for the AVAPS software](https://halodrops.readthedocs.io/en/latest/handbook/operations/pre_flight.html#test-chassis-cards)](static/gui_example.png){width="50%"}
 
+::: {.smaller}
+see also [Apple Design Guidelines](https://developer.apple.com/design/human-interface-guidelines/color)
+:::
+
 ::: {.notes}
 * maybe you all got it right away that the blue font markes a link to the doku ;-)
 :::