contributors: Add SeongJae

Signed-off-by: SeongJae Park <sj38.park@gmail.com>

contributors.md

@@ -124,3 +124,4 @@ Thank you to all contributors:
 * [Dragonly](https://github.com/dragonly)
 * [Blameying](https://github.com/Blameying)
 * [Junsoo Lee](https://github.com/junsooo)
+* [SeongJae Park](https://github.com/sjp38)