chore: Update markdownlint configuration

Author: Terraform

.markdownlint.yaml

@@ -1,3 +1,17 @@
 ---
 default: true
-line-length: false
+
+# no-hard-tabs
+MD010:
+  code_blocks: false
+
+# no-multiple-blanks
+MD012:
+  maximum: 2
+
+# line-length
+MD013: false
+
+# no-duplicate-heading
+MD024:
+  siblings_only: true