RFC 1216 is promote ! to a type

Author: nikomatsakis

text/0000-bang-type.md renamed to text/1216-bang-type.md

@@ -1,7 +1,7 @@
 - Feature Name: bang_type
 - Start Date: 2015-07-19
-- RFC PR: (leave this empty)
-- Rust Issue: (leave this empty)
+- RFC PR: https://github.com/rust-lang/rfcs/pull/1216
+- Rust Issue: https://github.com/rust-lang/rust/issues/35121
 
 # Summary