[PATCH olang] docs: add DCO information on hacking page

[Johnny Richard <johnny@johnnyrichard.com>]

All contributions must be signed off by the author. There is a link to
the Developer Certificate of Origin version 1.1.

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>
---
I'm adding a link to the DCO document.  I'm not sure if this document
will survive for a long time.  Let me know if I should attach the DCO
text to our documentation.

 docs/pages/hacking.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/docs/pages/hacking.md b/docs/pages/hacking.md
index 7ebd4b3..ef88791 100644
--- a/docs/pages/hacking.md
+++ b/docs/pages/hacking.md
@@ -68,7 +68,11 @@ make check
 Submitting a patch
 ------------------
 
-Before submit a patch, ensure your code follows our coding style and is
+All contributors are required to "sign-off" their commits (using git commit -s)
+to indicate that they have agreed to the [Developer Certificate of
+Origin](https://developercertificate.org/).
+
+Before submit the patch, ensure the code follows our coding style and is
 well-tested. After that, you\'re good to follow the steps bellow.
 
 ### Step 1: Commit your changes
-- 
2.43.2