refactor(promotion.md): add pre-existing EOL

Author: ismailarilik

promotion.md

@@ -71,7 +71,8 @@ are evaluated. We thus can be more relaxed about promotion; in practice, what
 this means is that we will promote calls to arbitrary `const fn`, not just those
 marked `#[rustc_promotable]`.
 
-[See below][access-static] for another special case in promotion analysis: accesses and references to statics are only promoted inside other statics.
+[See below][access-static] for another special case in promotion analysis:
+accesses and references to statics are only promoted inside other statics.
 
 [warn-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1229-compile-time-asserts.md