doc: update proposed DCO and CoC

lifted verbatim from
https://github.com/nodejs/node/blob/master/CONTRIBUTING.md
then `/s/Node.js/node-gyp/`

CONTRIBUTING.md

@@ -1,53 +1,34 @@
-## Developer's Certificate of Origin 1.0
+# Contributing to node-gyp
+
+## Code of Conduct
+
+Please read the
+[Code of Conduct](https://github.com/nodejs/TSC/blob/master/CODE_OF_CONDUCT.md)
+which explains the minimum behavior expectations for node-gyp contributors.
+
+<a id="developers-certificate-of-origin"></a>
+## 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.
+  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
 
-## Code of Conduct
+* (c) The contribution was provided directly to me by some other
+  person who certified (a), (b) or (c) and I have not modified
+  it.
 
-This Code of Conduct is adapted from [Rust's wonderful
-CoC](http://www.rust-lang.org/conduct.html).
-
-* We are committed to providing a friendly, safe and welcoming
-  environment for all, regardless of gender, sexual orientation,
-  disability, ethnicity, religion, or similar personal characteristic.
-* Please avoid using overtly sexual nicknames or other nicknames that
-  might detract from a friendly, safe and welcoming environment for
-  all.
-* Please be kind and courteous. There's no need to be mean or rude.
-* Respect that people have differences of opinion and that every
-  design or implementation choice carries a trade-off and numerous
-  costs. There is seldom a right answer.
-* Please keep unstructured critique to a minimum. If you have solid
-  ideas you want to experiment with, make a fork and see how it works.
-* We will exclude you from interaction if you insult, demean or harass
-  anyone.  That is not welcome behavior. We interpret the term
-  "harassment" as including the definition in the [Citizen Code of
-  Conduct](http://citizencodeofconduct.org/); if you have any lack of
-  clarity about what might be included in that concept, please read
-  their definition. In particular, we don't tolerate behavior that
-  excludes people in socially marginalized groups.
-* Private harassment is also unacceptable. No matter who you are, if
-  you feel you have been or are being harassed or made uncomfortable
-  by a community member, please contact one of the channel ops or any
-  of the TC members immediately with a capture (log, photo, email) of
-  the harassment if possible.  Whether you're a regular contributor or
-  a newcomer, we care about making this community a safe place for you
-  and we've got your back.
-* Likewise any spamming, trolling, flaming, baiting or other
-  attention-stealing behavior is not welcome.
-* Avoid the use of personal pronouns in code comments or
-  documentation. There is no need to address persons when explaining
-  code (e.g. "When the developer")
+* (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.