[SE-0414] Fix Markdown

Author: ole

proposals/0414-region-based-isolation.md

@@ -1996,7 +1996,7 @@ also be ascertained by just reading the source.
 
 ## Acknowledgments
 
-This proposal is based on work from the PLDI 2022 paper (A Flexible Type System for Fearless Concurrency)[https://www.cs.cornell.edu/andru/papers/gallifrey-types/].
+This proposal is based on work from the PLDI 2022 paper [A Flexible Type System for Fearless Concurrency](https://www.cs.cornell.edu/andru/papers/gallifrey-types/).
 
 Thanks to Doug Gregor, Kavon Farvardin for early assistance to Joshua during his
 internship.