update links

Author: yyx990803

.github/CONTRIBUTING.md

@@ -2,6 +2,7 @@
 
 Hi! I’m really excited that you are interested in contributing to Vue.js. Before submitting your contribution though, please make sure to take a moment and read through the following guidelines.
 
+- [Code of Conduct](https://github.com/vuejs/vue/blob/dev/.github/CODE_OF_CONDUCT.md)
 - [Issue Reporting Guidelines](#issue-reporting-guidelines)
 - [Pull Request Guidelines](#pull-request-guidelines)
 - [Development Setup](#development-setup)

README.md

@@ -66,11 +66,11 @@ For questions and support please use the [Gitter chat room](https://gitter.im/vu
 
 ## Issues
 
-Please make sure to read the [Issue Reporting Checklist](https://github.com/vuejs/vue/blob/dev/CONTRIBUTING.md#issue-reporting-guidelines) before opening an issue. Issues not conforming to the guidelines may be closed immediately.
+Please make sure to read the [Issue Reporting Checklist](https://github.com/vuejs/vue/blob/dev/.github/CONTRIBUTING.md#issue-reporting-guidelines) before opening an issue. Issues not conforming to the guidelines may be closed immediately.
 
 ## Contribution
 
-Please make sure to read the [Contributing Guide](https://github.com/vuejs/vue/blob/dev/CONTRIBUTING.md) before making a pull request. If you have a Vue-related project/component/tool, add it with a pull-request to [this curated list](https://github.com/vuejs/awesome-vue)!
+Please make sure to read the [Contributing Guide](https://github.com/vuejs/vue/blob/dev/.github/CONTRIBUTING.md) before making a pull request. If you have a Vue-related project/component/tool, add it with a pull-request to [this curated list](https://github.com/vuejs/awesome-vue)!
 
 ## Changelog