Merge pull request 'linter' (#13) from linter into main

Reviewed-on: mephisto/clubbing-content#13

.drone.yml

@@ -8,6 +8,11 @@ steps:
 #    pull: if-not-exists
 #    commands:
 #    - printenv
+  - name: lint
+    image: osshelp/drone-linter
+    settings:
+      markdown_files:
+        - schedule/schedule.md
   - name: copy-file-over-scp
     image: appleboy/drone-scp
     settings: