MAINTAINERS: add @hinshun

@hinshun has been a very valuable contributor to the project,
especially for the solver component.

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

MAINTAINERS

@@ -151,6 +151,7 @@ made through a pull request.
 
 		people = [
 			"akihirosuda",
+			"hinshun",
 			"ijc",
 			"tiborvass",
 			"tonistiigi",
@@ -183,6 +184,11 @@ made through a pull request.
 	Email = "akihiro.suda.cz@hco.ntt.co.jp"
 	GitHub = "AkihiroSuda"
 
+	[people.hinshun]
+	Name = "Edgar Lee"
+	Email = "edgarhinshunlee@gmail.com"
+	GitHub = "hinshun"
+
 	[People.ijc]
 	Name = "Ian Campbell"
 	Email = "ian.campbell@docker.com"