Update _index.md

- Correct link to Configuration page

Author: frightener

content/en/docs/_index.md

@@ -127,7 +127,7 @@ running `Pod`. See [`BuildRun`](/docs/build/buildrun/) for more details.
 
 ## Further reading
 
-- [Configuration](/docs/configuration/)
+- [Configuration](/docs/build/configuration/)
 - Build controller observability
   - [Metrics](/docs/metrics/)
   - [Profiling](/docs/profiling/)