Add missing inline code delimiters around Vec<T>

src/doc/nomicon/phantom-data.md

@@ -56,7 +56,7 @@ Good to go!
 
 Nope.
 
-The drop checker will generously determine that Vec<T> does not own any values
+The drop checker will generously determine that `Vec<T>` does not own any values
 of type T. This will in turn make it conclude that it doesn't need to worry
 about Vec dropping any T's in its destructor for determining drop check
 soundness. This will in turn allow people to create unsoundness using