Merge pull request #1500 from fee1-dead/+const-traits_repo

Add repo for project-const-traits

Author: jackh726

repos/rust-lang/project-const-traits.toml

@@ -0,0 +1,8 @@
+org = "rust-lang"
+name = "project-const-traits"
+description = "Const Traits Project Group"
+homepage = "https://rust-lang.github.io/project-const-traits/"
+bots = []
+
+[access.teams]
+project-const-traits = "maintain"