Updates on docs

Author: AlexRogalskiy

why-the-dco.md

@@ -0,0 +1,32 @@
+# Why the DCO?
+
+We have tried to make it as easy as possible to make contributions. 
+This applies to how we handle the legal aspects of contribution.
+
+We simply ask that when submitting a patch for review,
+the developer must include a sign-off statement in the commit message.
+This is the same approach that the
+[Linux® Kernel community](http://elinux.org/Developer_Certificate_Of_Origin)
+uses to manage code contributions.
+
+Here is an example Signed-off-by line, which indicates that the submitter accepts the DCO:
+
+```
+Signed-off-by: John Doe <john.doe@hisdomain.com>
+```
+
+You can include this automatically when you commit a change
+to your local git repository using
+
+```bash
+$ git commit -s
+```
+
+By signing your work, you are confirming that the origin of the content
+makes it suitable to add to this project.  See
+[Developer Certificate of Origin (DCO)](https://developercertificate.org/).
+
+
+----
+License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/),
+Copyright Contributors to the OpenLineage project.