Update posts/2021-07-29-Rust-1.54.0.md

Co-authored-by: XAMPPRocky <4464295+XAMPPRocky@users.noreply.github.com>

Author: Mark-Simulacrum

posts/2021-07-29-Rust-1.54.0.md

@@ -83,7 +83,7 @@ The following methods and trait implementations were stabilized.
 ### Other changes
 
 There are other changes in the Rust 1.54.0 release:
-check out what changed in [Rust](XXX), [Cargo](XXX), and [Clippy](XXX).
+check out what changed in [Rust](https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1540-2021-07-29), [Cargo](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-154-2021-07-29), and [Clippy](https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md#rust-154).
 
 rustfmt has also been fixed in the 1.54.0 release to properly format nested
 out-of-line modules. This may cause changes in formatting to files that were