Update xml/System.Collections.Frozen/FrozenDictionary`2.xml

Co-authored-by: Carlos Sánchez López <[email protected]>

Author: eiriktsarpalis

xml/System.Collections.Frozen/FrozenDictionary`2.xml

@@ -1231,7 +1231,7 @@
           <see langword="true" /> if a lookup could be created; otherwise, <see langword="false" />.</returns>
         <remarks>
           This instance must be using a comparer that implements <see cref="T:System.Collections.Generic.IAlternateEqualityComparer`2"/> with
-          <typeparamref name="TAlternateKey"/> and <typeparamref name="TKey"/>. If it doesn't, the method will return false.
+          <typeparamref name="TAlternateKey"/> and <typeparamref name="TKey"/>. If it doesn't, the method will return <see langword="false" />.
         </remarks>
       </Docs>
     </Member>