LICENSE, README: Dedicate this work to public domain via CC0

LICENSE

@@ -0,0 +1,6 @@
+This work is dedicated to the public domain via the CC0 rights waiver:
+    https://creativecommons.org/publicdomain/zero/1.0/
+
+To the extent possible under law, Curt J. Sampson ([email protected]) has
+waived all copyright and related or neighboring rights to How to
+Safely Use Ruby::SSH. This work is published from Japan.

README.md

@@ -95,3 +95,25 @@ of the environment with the usual:
 I currently use 3.2.0, the latest stable version. Depending on how
 things progress both on my exploration of the 3.2 API and the release
 process of 4.0.0, I may change to using 4.x sooner or later.
+
+
+License
+-------
+
+<p xmlns:dct="http://purl.org/dc/terms/" xmlns:vcard="http://www.w3.org/2001/vcard-rdf/3.0#">
+  <a rel="license"
+     href="http://creativecommons.org/publicdomain/zero/1.0/">
+    <img src="http://i.creativecommons.org/p/zero/1.0/88x31.png" style="border-style: none;" alt="CC0" />
+  </a>
+  <br />
+  To the extent possible under law,
+  <a rel="dct:publisher"
+     href="http://github.com/c-j-s/ruby-ssh-safety">
+    <span property="dct:title">Curt J Sampson</span></a>
+  has waived all copyright and related or neighboring rights to
+  <span property="dct:title">How to Safely Use Ruby::SSH</span>.
+This work is published from:
+<span property="vcard:Country" datatype="dct:ISO3166"
+      content="JP" about="http://github.com/c-j-s/ruby-ssh-safety">
+  Japan</span>.
+</p>