Pull Request template for busy projects

PULL_REQUEST_TEMPLATE

<!--- Copy & paste card title in the Title field above (SJ-XXX Card name) -->

<!--- Before you open a PR: --->
<!--- !!! stick to maximum 8 Pull Requests open !!! --->
<!--- !!! make a code review at least once a day (before standup?) !!! --->

## Description
<!--- Describe your changes in detail -->

## Motivation and Context
<!--- Why is this change required? What problem does it solve? -->
<!--- If it fixes an open issue, please link to the issue here. -->

## How Has This Been Tested?
<!--- Please describe in detail how you tested your changes. -->
<!--- Include details of your testing environment, and the tests you ran to -->
<!--- see how your change affects other areas of the code, etc. -->

## Screenshots (if appropriate):

## Checklist:
<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
- [ ] Make sure its name is exactly the same as card
- [ ] It contains only changes required by card (branched off from master)
- [ ] Includes link to a card
- [ ] My code follows the code style of this project (no linter warnings introduced).
- [ ] I have added tests to cover my changes.

<!--- Branch naming conventions: --->
<!--- - SJ-XXX/feature/... for new features cards --->
<!--- - SJ-XXX/fix/... for new features cards (branched of master) --->
<!--- - SJ-XXX/hotfix/... for hotfixes (branched of production) --->