chore: add @vant/stylelint-config package (#4943)

packages/vant-stylelint-config/index.js

@@ -0,0 +1,11 @@
+module.exports = {
+  extends: ['stylelint-config-standard', 'stylelint-config-rational-order'],
+  rules: {
+    'order/properties-order': [],
+    'at-rule-no-unknown': null,
+    'number-leading-zero': null,
+    'no-descending-specificity': null,
+    'declaration-colon-newline-after': null,
+    'font-family-no-missing-generic-family-keyword': null
+  }
+};