Add <code> around use

src/content/chapter5_advanced_features/lesson01_use/en.html

@@ -5,7 +5,7 @@
   sometimes result in excessive indentation.
 </p>
 <p>
-  Gleam's use expression helps out here by enabling us to write code that uses
+  Gleam's <code>use</code> expression helps out here by enabling us to write code that uses
   callbacks in an unindented style, as shown in the code window.
 </p>
 
@@ -27,4 +27,4 @@
   This is a very capable and useful feature, but excessive application of
   <code>use</code> may result in unclear code, especially to beginners. Usually
   the regular function call syntax results in more approachable code!
-</p>
+</p>