Add 'Used By' section and GitHub Action to update it

.github/workflows/update-used-by.yml

@@ -0,0 +1,32 @@
+name: Update Used By Section
+
+on:
+  schedule:
+    - cron: '0 0 * * 0' # Runs every Sunday at midnight
+  workflow_dispatch: # Allows for manual triggering of the workflow
+
+jobs:
+  update-used-by:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    - name: Fetch repositories using this project
+      run: |
+        curl -H "Accept: application/vnd.github.v3+json" \
+        https://api.github.com/search/repositories?q=BlackMarlinExec+in:file \
+        > used_by_repos.json
+
+    - name: Update README
+      run: |
+        python update_readme.py
+
+    - name: Commit and push changes
+      run: |
+        git config --global user.name 'github-actions[bot]'
+        git config --global user.email 'github-actions[bot]@users.noreply.github.com'
+        git add README.md
+        git commit -m 'Update Used By section'
+        git push

blackmarlinexec_readme.py

@@ -0,0 +1,17 @@
+import json
+
+with open('used_by_repos.json') as f:
+    data = json.load(f)
+
+repos = data.get('items', [])
+
+with open('README.md', 'r') as f:
+    lines = f.readlines()
+
+start_idx = next(i for i, line in enumerate(lines) if line.strip() == "## Used By") + 1
+end_idx = next((i for i, line in enumerate(lines[start_idx:], start=start_idx) if line.startswith("##")), len(lines))
+
+new_lines = lines[:start_idx] + [f"- [{repo['full_name']}]({repo['html_url']}): {repo.get('description', 'No description available')}\n" for repo in repos] + lines[end_idx:]
+
+with open('README.md', 'w') as f:
+    f.writelines(new_lines)