add license and issue_template

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,24 @@
+### Before submitting a pull request, please make sure the following is done:
+
+### 提交 PR 前请确保完成以下内容:
+
+1. Fork [the repository](https://github.com/youzan/vant) and create your branch from `master`.
+2. Follow the [contributing guide](./CONTRIBUTING.md) to setup your develop environment.
+2. If you've added code that should be tested, add tests!
+3. If you've changed APIs, update the documentation.
+4. Ensure the test suite passes (`npm test`).
+5. Make sure your code lints (`npm run lint`).
+6. Describe your pull request.
+
+### 请认真写 PR 的标题，会用于生成 change log。
+
+### Please remove the above lines when you submit this pull request, also please fill in the changes you've made in this pull request.
+
+### 提交 PR 前 请把以上内容删除，并填写以下内容。
+
+Fixes #xx(issue number here), remove this line if no related issue.
+
+Changes you made in this pull request:
+
+- some change
+- another change