chore: ignore markdownlink rules

Ignore "no empty links" and "Single h1" as they are not compatible
with some of the mdbook features, esp in SUMMARY.md

Author: matchy233

.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+  "markdownlint.config": {
+    "MD042": false, // no emtpy link
+    "MD025": false // single title h1
+  }
+}