Add config example

README.md

@@ -8,7 +8,26 @@ particular order).
 gh extension install pycontribs/gh-pre
 ```
 
-Usage:
+## Configuration
+
+In order to use the tool you neeed to conmfigure the list of repositories it needs to check on each run:
+
+```yaml
+# ~/pre.yml
+repos:
+  - ansible/ansible-compat
+  - ansible/ansible-lint
+  - ansible/ansible-navigator
+  - ansible/ansible-creator
+  - ansible/molecule
+  - ansible/tox-ansible
+  - ansible/pytest-ansible
+  - ansible/ansible-development-environment
+  - ansible/ansible-dev-tools
+  - ansible/creator-ee
+```
+
+## Usage
 
 ```
 gh pre