Merge pull request moby#3674 from crazy-max/security-md

docs: missing security policy markdown file

Author: crazy-max

.github/SECURITY.md

@@ -0,0 +1,12 @@
+# Reporting security issues
+
+The project maintainers take security seriously. If you discover a security
+issue, please bring it to their attention right away!
+
+**Please _DO NOT_ file a public issue**, instead send your report privately to
+[[email protected]](mailto:[email protected]).
+
+Security reports are greatly appreciated, and we will publicly thank you for it
+(if you want to). We also like to send gifts—if you're into schwag, make
+sure to let us know. We currently do not offer a paid security bounty program,
+but are not ruling it out in the future.