Organized setup instructions (#115)

* Organized setup instructions

* update tets

* link checker action

* raise error upon broken link

* fix links

* fix links

* delete duplicated paragraph

.github/workflows/basic-tests.yml

@@ -34,7 +34,7 @@ jobs:
       run: |
         pytest ch04/01_main-chapter-code/tests.py
         pytest ch05/01_main-chapter-code/tests.py
-        pytest appendix-A/02_installing-python-libraries/tests.py
+        pytest setup/02_installing-python-libraries/tests.py
 
     - name: Validate Selected Jupyter Notebooks
       run: |

.github/workflows/check-links.yml

@@ -0,0 +1,24 @@
+name: Check Markdown Links
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  check-links:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+
+      - name: Install Markdown Link Checker
+        run: npm install -g markdown-link-check
+
+      - name: Find Markdown Files and Check Links
+        run: |
+          find . -name '*.md' -exec markdown-link-check {} \;