Including the DCO notice

CONTRIBUTING.md

@@ -5,6 +5,16 @@ We try to make it easy, and all contributions, even the smaller ones, are more t
 This includes bug reports, fixes, documentation, examples... 
 But first, read this page (including the small print at the end).
 
+## Legal
+
+All original contributions to Quarkus are licensed under the
+[ASL - Apache License](https://www.apache.org/licenses/LICENSE-2.0),
+version 2.0 or later, or, if another license is specified as governing the file or directory being
+modified, such other license.
+
+All contributions are subject to the [Developer Certificate of Origin (DCO)](https://developercertificate.org/).
+The DCO text is also included verbatim in the [dco.txt](dco.txt) file in the root directory of the repository.
+
 ## Reporting an issue
 
 This project uses Github issues to manage the issues. Open an issue directly in Github.

dco.txt

@@ -0,0 +1,37 @@
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.