Add a docs file for openssl. Mention where to get OpenSSL for Windows.

extra/openssl/openssl-docs.factor

@@ -0,0 +1,10 @@
+
+USING: help.syntax help.markup ;
+
+IN: openssl
+
+ARTICLE: "openssl" "OpenSSL"
+
+"Factor on Windows has been tested with this version of OpenSSL: "
+
+{ $url "http://www.openssl.org/related/binaries.html" } ;