Create github workflow for building sphinx, for syntax checks

.github/workflows/sphinx_check.yml

@@ -0,0 +1,50 @@
+name: "Pull Request Docs Check"
+on:
+- pull_request
+
+jobs:
+  docs:
+    runs-on: ubuntu-latest
+    steps:
+      #----------------------------------------------
+      #       check-out repo and set-up python
+      #----------------------------------------------
+      - name: Check out repository
+        uses: actions/checkout@v3
+      - name: Set up python
+        id: setup-python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+      #----------------------------------------------
+      #  -----  install & configure poetry  -----
+      #----------------------------------------------
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+          installer-parallel: true
+      #----------------------------------------------
+      #       load cached venv if cache exists
+      #----------------------------------------------
+      - name: Load cached venv
+        id: cached-poetry-dependencies
+        uses: actions/cache@v3
+        with:
+          path: .venv
+          key: venv-${{ runner.os }}-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('**/poetry.lock') }}
+      #----------------------------------------------
+      # install dependencies if cache does not exist
+      #----------------------------------------------
+      - name: Install dependencies
+        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
+        run: poetry install --no-interaction
+      #----------------------------------------------
+      # Run Sphinx build
+      #----------------------------------------------
+      - name: Build the sphinx documentation
+        uses: rickstaa/sphinx-action@master
+        with:
+          docs-folder: "./docs"
+          build-command: "poetry run sphinx-build -b html source _build"