add pr template

[atherdon]

# Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes # (issue)

## Type of change

Please delete options that are not relevant.

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] This change requires a documentation update

# How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

- [ ] Test A
- [ ] Test B

**Test Configuration**:
* Firmware version:
* Hardware:
* Toolchain:
* SDK:

# Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream modules

[atherdon]

THIS PROJECT IS IN MAINTENANCE MODE. We accept pull requests for Bug Fixes **ONLY**. NO NEW FEATURES ACCEPTED!

<!--- Provide a general summary of your changes in the Title above -->

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

## Related Issue
<!--- This project only accepts pull requests related to open issues -->
<!--- If suggesting a new feature or change, please discuss it in an issue first -->
<!--- If fixing a bug, there should be an issue describing it with steps to reproduce -->
<!--- Please link to the issue here: -->

## 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):

[atherdon]

PULL_REQUEST_TEMPLATE.md