updated README with playwright installation command, added pytest workflow

.github/workflows/pytest.yml

@@ -0,0 +1,15 @@
+name: Test
+
+on: [push]
+
+jobs:
+  pytest:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v3
+        with:
+          python-version: '3.9'
+      - run: pip install -e .[dev]
+      - run: python -m playwright install
+      - run: pytest --exitfirst --failed-first

README.md

@@ -8,6 +8,7 @@ The tool helps to download posts and videos from TikTok for a given set of hasht
 1. Make sure you have Python 3.9 or a later version installed
 2. Install the tool with pip: `pip install tiktok-hashtag-analysis`
    - Alternatively you can install directly from the latest version on GitHub: `pip install git+https://github.com/bellingcat/tiktok-hashtag-analysis`
+3. Make sure [Playwright](https://playwright.dev/python/docs/intro) is properly installed byrunning the command `python -m playwright install`
 
 You should now be ready to start using it.