message: docs: fix the snippets in rules import closes
diff: @@ -87,10 +87,10 @@ You can import all rules with ES6 like this:
  ```js
  import { extend } from 'vee-validate';
  -import * as Rules from 'vee-validate/dist/rules';
  +import * as rules from 'vee-validate/dist/rules';
  // loop over all rules
  -for (rule in Rules) {
  +for (let rule in rules) {
  // add the rule
  extend(rule, rules[rule]);
  }
  @@ -102,11 +102,11 @@ VeeValidate also has default messages for those rules, which you can import and
  ```js
  import { extend } from 'vee-validate';
  -import * as Rules from 'vee-validate/dist/rules';
  +import * as rules from 'vee-validate/dist/rules';
  import en from 'vee-validate/dist/locale/en';
  // loop over all rules
  -for (rule in Rules) {
  +for (let rule in rules) {
  extend(rule, {
  ...rules[rule], // add the rule
  message: en.messages[rule] // add its message
  