Write new pull request template (#12100)

PULL_REQUEST_TEMPLATE.md

@@ -1,8 +1,16 @@
-case 1. Add a new type definition.
-- [ ] checked compilation succeeds with `--target es6` and `--noImplicitAny` options.
-- [ ] has correct [naming convention](http://definitelytyped.org/guides/contributing.html#naming-the-file)
-- [ ] has a [test file](http://definitelytyped.org/guides/contributing.html#tests) with the suffix of  `-tests.ts` or `-tests.tsx`.
+Please fill in this template.
 
-case 2. Improvement to existing type definition.
-- documentation or source code reference which provides context for the suggested changes.  url http://api.jquery.com/html .
-  - it has been reviewed by a DefinitelyTyped member.
+- [ ] Prefer to make your PR against the `types-2.0` branch.
+- [ ] The package does not provide its own types, and you can not add them.
+- [ ] Test the change in your own code.
+- [ ] Follow the advice from the [readme](https://github.com/DefinitelyTyped/DefinitelyTyped#make-a-pull-request).
+- [ ] Avoid [common mistakes](https://github.com/DefinitelyTyped/DefinitelyTyped#common-mistakes).
+
+If adding a new definition:
+- [ ] If this is for an NPM package, match the name. If not, do not conflict with the name of an NPM package.
+- [ ] Run `tsc` without errors.
+- [ ] Include the required [files](https://github.com/DefinitelyTyped/DefinitelyTyped#create-a-new-package) and header.
+
+If changing an existing definition:
+- [ ] Provide a URL to  documentation or source code which provides context for the suggested changes: <<url here>>
+- [ ] Increase the version number in the header if appropriate.