elo: add live leaderboard

Cargo.lock

@@ -172,6 +172,15 @@ dependencies = [
  "itertools",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06ba6d68e24814cb8de6bb986db8222d3a027d15872cabc0d18817bc3c0e4471"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -415,6 +424,7 @@ dependencies = [
  "arrayvec",
  "const_fn",
  "criterion",
+ "crossbeam-channel",
  "either",
  "indicatif",
  "nohash-hasher",