Add ToC lint

.github/workflows/lint.yml

@@ -28,3 +28,17 @@ jobs:
         uses: actions/checkout@v2
       - name: Check for editorconfig violations
         uses: editorconfig-checker/action-editorconfig-checker@v1
+
+  lint-markdown-toc:
+    runs-on: ubuntu-latest
+    name: Lint for Table of Contents
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@v2
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'npm'
+      - run: npm install markdown-toc
+      - run: ./node_modules/.bin/markdown-toc -i README.md
+      - run: git diff --exit-code

.gitignore

@@ -1,3 +1,4 @@
 .idea/
 .vscode/
 target/
+node_modules/

README.md

@@ -6,6 +6,7 @@ If you want to contribute, please read [this](CONTRIBUTING.md).
 
 ## Table of contents
 
+<!-- toc -->
   - [Applications](#applications)
     - [Audio and Music](#audio-and-music)
     - [Cryptocurrencies](#cryptocurrencies)
@@ -101,6 +102,8 @@ If you want to contribute, please read [this](CONTRIBUTING.md).
   - [Resources](#resources)
   - [License](#license)
 
+<!-- tocstop -->
+
 ## Applications
 
 See also [Rust — Production](https://www.rust-lang.org/production) organizations running Rust in production.