minor fixes

Author: mark-i-m

src/stability.md

@@ -3,7 +3,8 @@
 This section is about the stability attributes and schemes that allow stable APIs to use unstable
 APIs internally in the rustc standard library.
 
-For instructions on stabilizing a language feature see [Stabilizing Features](./stabilization_guide.md).
+For instructions on stabilizing a language feature see 
+[Stabilizing Features](./stabilization_guide.md).
 
 # unstable
 
@@ -34,9 +35,11 @@ Note that `const fn`s are even more special in this regard. You can't just white
 the features need an implementation in `qualify_min_const_fn.rs`. For example the `const_fn_union`
 feature gate allows accessing fields of unions inside stable `const fn`s. The rules for when it's
 ok to use such a feature gate are that behavior matches the runtime behavior of the same code
-(see also https://www.ralfj.de/blog/2018/07/19/const.html). This means that you may not create a
+(see also [this blog post][blog]). This means that you may not create a
 `const fn` that e.g. transmutes a memory address to an integer, because the addresses of things
 are nondeterministic and often unknown at compile-time.
 
 Always ping @oli-obk, @RalfJung, and @Centril if you are adding more `allow_internal_unstable`
 attributes to any `const fn`
+
+[blog]: https://www.ralfj.de/blog/2018/07/19/const.html