Missed a review comment

Co-authored-by: LeSeulArtichaut <[email protected]>

Author: jyn514

src/building/bootstrapping.md

@@ -192,7 +192,7 @@ Note that there are two `std` libraries in play here:
 2. The library _used to compile programs_ with `stageN/rustc`, which was
    built by stage N (stage N `std`).
 
-stage N `std` is pretty much necessary for any useful work with the stage N compiler.
+Stage N `std` is pretty much necessary for any useful work with the stage N compiler.
 Without it, you can only compile programs with `#![no_core]` -- not terribly useful!
 
 The reason these need to be different is because they aren't necessarily ABI-compatible: