Format / Sort COMMITTERS.md; Add Yujie Chen to Active list

Before, the list was newline separated. Unfortunately this renders into html as a single line. This change switches to using *s instead.

It also adds Yujie Chen to the list.

Bugs closed: 4061

Reviewed at https://rbcommons.com/s/twitter/r/4382/

COMMITTERS.md

@@ -1,28 +1,29 @@
 Active Committers
 =================
 
-Nick Howard
-Benjy Weinberger
-Chris Heisterkamp
-Matt Olsen
-Eric Ayers
-Fedor Korotkov
-Garrett Malmquist
-Ity Kaul
-John Sirois
-Kris Wilson
-Larry Hosken
-Mateo Rodriguez
-Patrick Lawson
-Peiyu Wang
-Stu Hood
-Tejal Desai
-Yi Cheng
+* Benjy Weinberger
+* Chris Heisterkamp
+* Eric Ayers
+* Fedor Korotkov
+* Garrett Malmquist
+* Ity Kaul
+* John Sirois
+* Kris Wilson
+* Larry Hosken
+* Mateo Rodriguez
+* Matt Olsen
+* Nick Howard
+* Patrick Lawson
+* Peiyu Wang
+* Stu Hood
+* Tejal Desai
+* Yi Cheng
+* Yujie Chen
 
 Emeritus
 ========
 
-Andy Reitz
-David Taylor
-David Turner
-Travis Crawford
+* Andy Reitz
+* David Taylor
+* David Turner
+* Travis Crawford