Move to Linkspector (#96)

# Move to Linkspector

## ⚙️ Release Notes 
- Replace Markdown Link check with Linkspector

### Code of Conduct & Contributing Guidelines 

By submitting creating this pull request, you agree to follow our [Code
of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md):
- [x] I agree to follow the [Code of
Conduct](https://github.com/StanfordBDHG/.github/blob/main/CODE_OF_CONDUCT.md)
and [Contributing
Guidelines](https://github.com/StanfordBDHG/.github/blob/main/CONTRIBUTING.md).

---------

Signed-off-by: Paul Schmiedmayer <PSchmiedmayer@users.noreply.github.com>

.github/workflows/markdown-link-check.yml

@@ -6,15 +6,42 @@
 # SPDX-License-Identifier: MIT
 #
 
-name: Check README Links
+name: Check Links
 
 on:
   workflow_call:
 
 jobs:
   markdown_link_check:
+    name: Check Links
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Markdown Link Check
-        uses: gaurav-nelson/github-action-markdown-link-check@v1
+      - uses: actions/checkout@v4
+      - name: Linkspector Ubuntu Workaround
+        run: |
+          echo "Linkspector Ubuntu Workaround for: https://github.com/UmbrellaDocs/action-linkspector/issues/32"
+          echo 0 | sudo tee /proc/sys/kernel/apparmor_restrict_unprivileged_userns
+      - name: Check and Create Linkspector Configuration
+        run: |
+          CONFIG_FILE=".linkspector.yml"
+          if [ ! -f "$CONFIG_FILE" ]; then
+            echo "Configuration file not found. Creating a new one."
+            echo "dirs:" >> $CONFIG_FILE
+            echo "  - ." >> $CONFIG_FILE
+            echo "useGitIgnore: true" >> $CONFIG_FILE
+            echo "ignorePatterns:" >> $CONFIG_FILE
+            echo "  - pattern: '^doc:.*$'" >> $CONFIG_FILE
+            echo "replacementPatterns:" >> $CONFIG_FILE
+            echo "  - pattern: '(.*)#gh-dark-mode-only'" >> $CONFIG_FILE
+            echo "    replacement: '\$1'" >> $CONFIG_FILE
+            echo "  - pattern: '(.*)#gh-light-mode-only'" >> $CONFIG_FILE
+            echo "    replacement: '\$1'" >> $CONFIG_FILE
+          else
+            echo "Configuration file exists. Skipping creation."
+          fi
+          echo "Contents of $CONFIG_FILE:"
+          cat $CONFIG_FILE
+      - name: Linkspector
+        uses: umbrelladocs/action-linkspector@v1
+        with:
+          filter_mode: nofilter