Fix a link to the README in the documentation.
diff --git a/docs/introduction.md b/docs/introduction.md
index d45d622..4e4932e 100644
--- a/docs/introduction.md
+++ b/docs/introduction.md
@@ -151,7 +151,7 @@
 http://web-platform.test:8000/<br>
 https://web-platform.test:8443/ *
 
-\**See [Trusting Root CA](README.md#trusting-root-ca)*
+\**See [Trusting Root CA](https://github.com/w3c/web-platform-tests/blob/master/README.md#trusting-root-ca)*
 
 ## Running tests automatically