Build: Exclude twitter.com from spider-check

```
- url:     https://twitter.com/qunitjs
  error:   The HTTP server returned a redirect error that would lead to an infinite loop.
```

.github/configs/hydra-config.json

@@ -0,0 +1,5 @@
+{
+  "exclude_scheme_prefixes": [
+    "https://twitter.com/"
+  ]
+}

.github/workflows/spider-check.yaml

@@ -26,9 +26,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-        with:
-          repository: jquery/hydra-link-checker
-          ref: v2.0.0
 
       - name: Run hydra-link-checker
-        run: python3 hydra.py "$MY_SITE"
+        run: |
+          curl -O https://raw.githubusercontent.com/jquery/hydra-link-checker/v2.0.0/hydra.py
+          python3 hydra.py "$MY_SITE" --config .github/configs/hydra-config.json

docs/config.md

@@ -44,7 +44,7 @@ amethyst:
   #
   # Example: https://github.com/qunitjs/qunit/releases/tag/
   release_base:
-  # Mastodon account URL (e.g. "https://mastodon.technology/@qunitjs")
+  # Mastodon account URL (e.g. "https://example.org/@qunitjs")
   mastodon:
   # Twitter.com username (without "@")
   twitter:

index.md

@@ -38,7 +38,7 @@ home_secondary_btn:
 
 ## Join the Community
 
-<p class="lead lead--center" markdown="1">Join us on [Mastodon](https://mastodon.technology/@qunitjs), [Twitter](https://twitter.com/qunitjs), or [Gitter chat](https://gitter.im/qunitjs/qunit).</p>
+<p class="lead lead--center" markdown="1">Follow us on [Mastodon](https://qunitjs.com#mastodon), or join our [Matrix chat](https://qunitjs.com#matrix).</p>
 
 To contribute: