Add Contribution section to README.rst

README.rst

@@ -1076,3 +1076,25 @@ BaseRequestHandler usage:
     # give None to ssl to make the server non-SSL/TLS
     server = nghttp2.HTTP2Server(('127.0.0.1', 8443), Handler, ssl=ctx)
     server.serve_forever()
+
+Contribution
+------------
+
+[This text was composed based on 1.2. License section of curl/libcurl
+project.]
+
+When contributing with code, you agree to put your changes and new
+code under the same license nghttp2 is already using unless stated and
+agreed otherwise.
+
+When changing existing source code, you do not alter the copyright of
+the original file(s).  The copyright will still be owned by the
+original creator(s) or those who have been assigned copyright by the
+original author(s).
+
+By submitting a patch to the nghttp2 project, you are assumed to have
+the right to the code and to be allowed by your employer or whatever
+to hand over that patch/code to us.  We will credit you for your
+changes as far as possible, to give credit but also to keep a trace
+back to who made what changes.  Please always provide us with your
+full real name when contributing!