add config setup instructions

README.md

@@ -4,6 +4,20 @@ Quick tool to write gemtext posts for my gemlog.
 
 => gemini://travisshears.com/gemlog
 
+## Config setup
+
+This app relys on a config file at `~/.config/gemlog-cli/config.yml`
+
+With the following format:
+
+```yaml
+couchdb:
+  host: http://myhost
+  port: 1234
+  user: gemlog-cli
+  password: xxxxxxxxxxxxxxxxxxxxxxxxxxx
+```
+
 ## Dev
 
 To run command locally: