fix path

Author: tshepang

src/contributing.md

@@ -387,7 +387,7 @@ Just a few things to keep in mind:
     - jan 2021
     - january 2021
 
-    There is a CI action (in `~/.github/workflows/date-check.yml`)
+    There is a CI action (in `.github/workflows/date-check.yml`)
     that generates a monthly report showing those that are over 6 months old
     ([example](https://github.com/rust-lang/rustc-dev-guide/issues/2052)).