fix typo maker -> marker (thanks @LHolten)

jdonszelmann · tshepang · commit 1874fe23238e · 2024-09-08T14:01:27.000+02:00
diff --git a/src/coherence.md b/src/coherence.md
@@ -35,7 +35,7 @@ In both cases, all pairs of impls are checked for overlap.
 
 Overlapping is sometimes partially allowed:
 
-1. for maker traits
+1. for marker traits
 2. under [specialization](./specialization.md)
 
 but normally isn't. 
