Add metadata validation test

* Incorrect readme block publish

Author: penguinolog

.github/workflows/pythonpackage.yml

@@ -92,6 +92,25 @@ jobs:
   #      - name: Check imports sorting with isort
   #        run: |
   #          isort -c --diff logwrap
+  Metadata:
+    name: Validate metadata
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.x'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install --upgrade twine build
+      - name: Build package
+        run: |
+          python -m build -s
+      - name: Validate metadata
+        run: |
+          twine check dist/*
 
   Test:
     needs: [PEP8, PyLint, MyPy, Black]  # isort is broken

README.rst

@@ -376,6 +376,6 @@ The main test mechanism for the package `logwrap` is using `tox`.
 Available environments can be collected via `tox -l`
 
 CI/CD systems
-==========
+=============
 
 `GitHub: <https://github.com/python-useful-helpers/logwrap/actions>`_ is used for functional tests.