add validation to metadata

Author: hectorsector

config.yml

@@ -417,6 +417,16 @@ steps:
   description: Add some descriptions to your course
   event: pull_request.synchronize
   actions:
+  - type: getFileContents
+    action_id: fileContents
+    filename: 'config.yml'
+  - type: gate
+    left: '/^tagline:(?![ \t]*#).*$\ndescription:(?![ \t]*#).*$/gm'
+    operator: test
+    right: '%actions.fileContents%'
+    else:
+    - type: respond
+      with: e-no-meta.md  
   - type: respond
     with: add-readme.md
 

responses/e-no-meta.md

@@ -0,0 +1 @@
+I didn't find metadata. Add it.