add code-editors redirect

Author: mansona

_redirects

@@ -18,6 +18,7 @@
 / https://cli.emberjs.com/release/ 301!
 /user-guide https://cli.emberjs.com/release/ 301!
 /extending https://cli.emberjs.com/release/ 301!
+/editors https://guides.emberjs.com/release/code-editors/ 301!
 
 http://blog.ember-cli.com https://cli.emberjs.com/release/ 301!
 https://blog.ember-cli.com https://cli.emberjs.com/release/ 301!