deleted unnecessary `the`

src/doc/trpl/references-and-borrowing.md

@@ -3,7 +3,7 @@
 This guide is one of three presenting Rust’s ownership system. This is one of
 Rust’s most unique and compelling features, with which Rust developers should
 become quite acquainted. Ownership is how Rust achieves its largest goal,
-memory safety. The there are a few distinct concepts, each with its own
+memory safety. There are a few distinct concepts, each with its own
 chapter:
 
 * [ownership][ownership], ownership, the key concept