Added markdown-include to dependencies

Author: hng

.github/workflows/ci.yml

@@ -13,6 +13,6 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: 3.x
-      - run: pip install mkdocs-material
+      - run: pip install mkdocs-material markdown-include
       - run: sed -i '/<!-- MKDOCS IGNORE -->/,/<!-- MKDOCS IGNORE -->/d' README.md
       - run: mkdocs gh-deploy --force