message: Fix a typo in src/libs/maintining-std.md
  Fix a typo in src/libs/maintining-std.md
diff: @@ -48,7 +48,7 @@ The rules around what's sound and what's not can be subtle. See the [Unsafe Code
  Inlining is a trade-off between potential execution speed, compile time and code size. There's some discussion about it in [this PR to the `hashbrown` crate][hashbrown/pull/119]. From the thread:
  -> `#[inline]` is very different than simply just an inline hint. As I mentioned before, there's no equivalent in C++ for what `#[inline]` does. In debug mode rustc basically ignores `#[inline]`, pretending you didn't even write it. In release mode the compiler will, by default, codegen an `#[inline]` function into every single referencing codegen unit, and then it will also add `inlinehin`t. This means that if you have 16 CGUs and they all reference an item, every single one is getting the entire item's implementation inlined into it.
  +> `#[inline]` is very different than simply just an inline hint. As I mentioned before, there's no equivalent in C++ for what `#[inline]` does. In debug mode rustc basically ignores `#[inline]`, pretending you didn't even write it. In release mode the compiler will, by default, codegen an `#[inline]` function into every single referencing codegen unit, and then it will also add `inlinehint`. This means that if you have 16 CGUs and they all reference an item, every single one is getting the entire item's implementation inlined into it.
  You can add `#[inline]`:
  