tokio: fix broken contributing guide link (#2267)

The link to the contributing guide in the tokio sub crate was referencing a non-existent file. This updates the link to reference the repo root's CONTRIBUTING.md file. Fixes: #2266
tokio-rs · Feb 23, 2020 · 4213b79 · 4213b79
1 parent 7b8ce35
commit 4213b79
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/README.md b/README.md
@@ -110,7 +110,7 @@ question. Last, if that doesn't work, try opening an [issue] with the question.
 you! We have a [contributing guide][guide] to help you get involved in the Tokio
 project.
 
-[guide]: CONTRIBUTING.md
+[guide]: https://github.com/tokio-rs/tokio/blob/master/CONTRIBUTING.md
 
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