Update some text about borrow checking for accuracy

There's a common misconception that the borrow checker contributes
substantially to Rust compilation time. However, this isn't the case;
borrow checking is not a substantial part of compilation time.

Author: joshtriplett

content/en/docs/c3.lifetimes.md

@@ -23,9 +23,9 @@ In Rust,
 * When dealing with **references**, we have to specify **lifetime annotations** to provide instructions for the **compiler** to set **how long** those referenced resources **should be alive**.
 * ⭐ But because of lifetime annotations make the **code more verbose**, in order to make **common patterns** more ergonomic, Rust allows lifetimes to be **elided/omitted** in `fn` definitions. In this case, the compiler assigns lifetime annotations **implicitly**.
 
-Lifetime annotations are **checked at compile-time**. Compiler checks when a data is used for the first and the last times. According to that, Rust manages memory in **run time**. This is the major reason for **slower compilation times** in Rust.
+Lifetime annotations are **checked at compile-time**. The compiler checks when data is used for the first and the last times.
 
-> * Unlike C and C++, **usually**, Rust doesn’t explicitly drop values at all.
+> * Unlike C and C++, **usually**, Rust doesn’t require explicitly dropping values at all.
 > * Unlike GC, Rust doesn’t place deallocation calls where the data is no longer referenced.
 > * Rust places deallocation calls where the data is about to go out of the scope and then enforces that no references to that resource exist after that point.