Fix typo in "Some other build system" page

Author: dtolnay

book/src/build/other.md

@@ -8,7 +8,7 @@ You will need to achieve at least these three things:
 - Link the resulting objects together with your other C++ and Rust objects.
 
 *Not all build systems are created equal. If you're hoping to use a build system
-from the '90s, especially if you're hoping to overlaying the limitations of 2 or
+from the '90s, especially if you're hoping to overlay the limitations of 2 or
 more build systems (like automake+cargo) and expect to solve them
 simultaneously, then be mindful that your expectations are set accordingly and
 seek sympathy from those who have imposed the same approach on themselves.*