Auto merge of #9963 - ehuss:highfive-triagebot, r=xFrednet

Migrate from highfive to triagebot

This migrates this repository from using the highfive bot to using triagebot (aka rustbot).

This should not be merged without coordinating the removal of the highfive webhook and/or merging rust-lang/highfive#435.

changelog: none

triagebot.toml

@@ -4,9 +4,23 @@ allow-unauthenticated = [
     "good-first-issue"
 ]
 
-[assign]
-
 # Allows shortcuts like `@rustbot ready`
 #
 # See https://github.com/rust-lang/triagebot/wiki/Shortcuts
 [shortcut]
+
+[assign]
+contributing_url = "https://github.com/rust-lang/rust-clippy/blob/master/CONTRIBUTING.md"
+
+[assign.owners]
+"/.github" = ["@flip1995"]
+"*" = [
+    "@flip1995",
+    "@Manishearth",
+    "@llogiq",
+    "@giraffate",
+    "@xFrednet",
+    "@Alexendoo",
+    "@dswij",
+    "@Jarcho",
+]