ci: Update main.yml

.github/workflows/main.yml

@@ -17,9 +17,7 @@ jobs:
         uses: actions/setup-python@v2
 
       - name: Install dependencies
-        run: |
-          python -m pip install --upgrade pip
-          pip install -r requirements.txt
+        run: make install
 
       - name: Build and deploy
         run: mkdocs gh-deploy --strict