Add note about DCO sign-off

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

Author: cpuguy83

CONTRIBUTING.md

@@ -25,7 +25,7 @@ Dalec has adopted the CNCF Code of Conduct. Refer to our [Community Code of Cond
 2. Fork the desired repository, then develop and test your code changes.
 3. Submit a pull request.
 
-When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
+When you submit a pull request all commits must include a [DCO signed-off](https://wiki.linuxfoundation.org/dco).
 
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