AddPRtemplateforgithub

What is this PR for?

PR template can be added automatically by GitHub when a PR is opened.
https://help.github.com/articles/creating-a-pull-request-template-for-your-repository/
Proposing some changes to PR template wordings.

What type of PR is it?

Improvement

Todos

• [x] - Add template

Is there a relevant Jira issue?

N/A

How should this be tested?

Open a new PR.

Screenshots (if appropriate)

N/A

Questions:

• Does the licenses files need update? N/A


• Is there breaking changes for older versions? N/A


• Does this needs documentation? N/A

该提问来源于开源项目：apache/zeppelin