Add link to Async Rust is about concurrency, not (just) performance blog post

Author: Kobzol

draft/2025-01-15-this-week-in-rust.md

@@ -42,6 +42,8 @@ and just ask the editors to select the category.
 
 ### Observations/Thoughts
 
+* [Async Rust is about concurrency, not (just) performance](https://kobzol.github.io/rust/2025/01/15/async-rust-is-about-concurrency.html)
+
 ### Rust Walkthroughs
 * [video] [CppCon - C++/Rust Interop: Using Bridges in Practice](https://tylerjw.dev/posts/20240920-cppcon-cpp-rust-interop/)