implement automated generation of table of content

.github/workflows/auto_table_of_content.yml

@@ -0,0 +1,18 @@
+on:
+  push:
+    branches: [master]
+    paths: ['README.md']
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          curl https://raw.githubusercontent.com/ekalinin/github-markdown-toc/master/gh-md-toc -o gh-md-toc
+          chmod a+x gh-md-toc
+          ./gh-md-toc --insert --no-backup README.md
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: Auto update markdown TOC