Install pandoc

Author: richelbilderbeek

.github/workflows/check_spelling.yaml

@@ -18,6 +18,8 @@ jobs:
       - name: Set up Git repository
         uses: actions/checkout@v4.2.0
 
+      - uses: docker://pandoc/core:3.8
+
       - name: Remove folders that do not care about spelling
         run: |
           rm -rf LICENSE.md