Add file 'Configuration.md'

Configuration.md

+# Configuration
+
+ * `database_file`:
+ * `host`
+ * `port`:
+ * `template`:
+ * `self_url`:
+ * `cookie_signing_secret`:
+ * `require_sex`:
+ * `allow_sex_na`:
+ * `allow_sex_diverse`:
+ * `allow_sex_other`:
+ * `server_message`:
+ * `oauth_providers`:
\ No newline at end of file