Update readme

Author: tbsklg

README.md

@@ -15,11 +15,21 @@ strikes ls
 You can use the local client without a remote server.
 It will generate a JSON file where the strikes are stored. 
 The default path is in your home directory at '.strikes/db.json'.
-You can configure a different location by using the '--db_path' argument.
+You can configure a different location by using the '--db_path' argument or by providing a configuration file.
+The argument has precedence over the configuration file.
+
+```bash
+
+### Configuration file
+The configuration file needs to be a yaml file.
+
+```yaml
+db_path: /path/to/db.json
+```
 
 The following command will create a database (db.json) in the current directory.
 
 ```bash
-strikes --db_path . strike guenther
+strikes --db_path . strike <user>
 ```