triagebot: fix incorrect link

Author: jieyouxu

triagebot.toml

@@ -22,8 +22,8 @@ remove_labels = ["S-waiting-on-author"]
 # Those labels are added when PR author requests a review from an assignee
 add_labels = ["S-waiting-on-review"]
 
-# Enable tracking of PR review assignment
-# Documentation at: https://forge.rust-lang.org/triagebot/pr-assignment-tracking.html
+# Enable shortcuts like `@rustbot ready`
+# Documentation at: https://forge.rust-lang.org/triagebot/shortcuts.html
 [shortcut]
 
 [autolabel."S-waiting-on-review"]