Run vale on .asciidoc rather than .md

Author: spier

.github/workflows/vale.yml

@@ -5,7 +5,7 @@ on:
     branches:
     - main
     paths:
-    - '**.md'
+    - '**.asciidoc'
   pull_request:
     branches:
     - main
@@ -20,4 +20,4 @@ jobs:
     - name: Vale Linting
       uses: errata-ai/vale-action@reviewdog
       with:
-        files: '["product/*.md"]'
+        files: '["product/*.asciidoc"]'