Title Case for line-up title (#2598)

Author: glennj

exercises/line-up/metadata.toml

@@ -1,4 +1,4 @@
-title = "Line up"
+title = "Line Up"
 blurb = "Help lining up customers at Yaʻqūb's Deli."
 source = "mk-mxp, based on previous work from Exercism contributors codedge and neenjaw"
 source_url = "https://forum.exercism.org/t/new-exercise-ordinal-numbers/19147"