Add hosts and default index file

hosts/default/index.gemini

@@ -0,0 +1,13 @@
+# Success!
+Your Gemini server is up and running!
+
+You can read more about this server at
+=> gemini://glasgow.social/gemini-php
+
+Join the community on Matrix at #gemini-php:glasgow.social
+
+## Getting Started
+Let's take 'gemini.com' as an example.
+* Generate a certificate and place it in the 'certs' directory named gemini.com.pem
+* Create a directory to server files from in the 'hosts' directory named gemini.com (e.g. mkdir hosts/gemini.com)
+* A file called index.gemini will be served if you haven't specified a path (this file is located at hosts/default/index.gemini)