Issue template example (#5073)

Author: caioincau

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,3 +2,39 @@
 Please make sure to read the Pull Request Guidelines:
 https://github.com/vuejs/vue/blob/dev/.github/CONTRIBUTING.md#pull-request-guidelines
 -->
+
+<!-- ISSUE TEMPLATE -->
+**Please check if the PR fulfills these requirements**
+- [ ] Do not submit PRs against the master branch.
+- [ ] Checkout a topic branch from the relevant branch, e.g. dev, and merge back against that branch.
+- [ ] The tests are running: https://github.com/vuejs/vue/blob/dev/.github/CONTRIBUTING.md#development-setup
+
+If adding new feature:
+- [ ] Added accompanying test case.
+- [ ] In the commit message, provide convincing reason to add this feature.
+      Ideally you should open a suggestion issue first and have it greenlighted before working on it.
+
+If fixing a bug:
+- [ ] If you are resolving a special issue, add (fix #xxxx[,#xxx]) (#xxxx is the issue id) in your PR title
+- [ ] Provide detailed description of the bug in the PR. Live demo preferred.
+- [ ] Add appropriate test coverage if applicable.
+
+**What kind of change does this PR introduce?** (check at least one with "x")
+```
+[ ] Bugfix
+[ ] Feature
+[ ] Code style update
+[ ] Refactoring
+[ ] Build related changes
+[ ] Other... Please describe:
+```
+
+**Does this PR introduce a breaking change?** (check one with "x")
+```
+[ ] Yes
+[ ] No
+```
+
+If this PR contains a breaking change, please describe the impact and migration path for existing applications:
+
+**Other information**: