document describing how to use amber SSL (#149)

contains instructions on how to enable SSL for amber

guides/ssl.md

@@ -0,0 +1,23 @@
+# SSL
+
+For development use self-signed keys and edit ```config/environments/development.yml```
+
+```
+ssl_key_file: example.key
+ssl_cert_file: example.crt
+```
+
+For production, please use CertBot (https://certbot.eff.org) and edit ```config/environments/production.yml```
+
+It is possible to set this in your Amber configure block as well, in ```config/application.cr```
+
+```
+Amber::Server.configure do |setting|
+  # Server options
+  setting.name = "Example web application."
+  setting.port = 3000 # Port you wish your app to run
+  setting.host = "0.0.0.0"
+  setting.ssl_key_file = "example.key"
+  setting.ssl_cert_file = "example.crt"
+end
+```