Install all requirements in documentation workflow

Author: Electronic-Mango

.github/workflows/documentation.yml

@@ -16,6 +16,9 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3
+      - name: Install requirements
+        run: |
+          pip install -r requirements.txt
       - name: Install dependencies
         run: |
           pip install sphinx sphinx_rtd_theme myst_parser