chore(lint): Add markdown linting rules [skip ci]

Author: LukeSavefrogs

.markdownlint.json

@@ -0,0 +1,11 @@
+{
+  "MD013": false,
+  "MD024": {
+    "siblings_only": true
+  },
+  "MD031": {
+    "list_items": false
+  },
+  "MD032": false,
+  "MD033": false
+}