Update PR template to be concise with checklist (#73)

This PR simplifies PR template to have 3 sections, "Description", "Issue" and  "Checklist". The check list provides overview on tests and documentation with respect to changes that are part of this PR.

## Issue
There is no issue created for this requirement.

Authors:
  - Ramakrishnap (https://github.com/rgsl888prabhu)

Approvers:
  - James Lamb (https://github.com/jameslamb)

URL: #73

Author: rgsl888prabhu

.github/PULL_REQUEST_TEMPLATE.md

@@ -4,41 +4,27 @@ Thank you for contributing to cuOpt :)
 
 Here are some guidelines to help the review process go smoothly.
 
-1. Please write a description in this text box of the changes that are being
-   made.
-
-2. Please ensure that you have written units tests for the changes made/features
-   added.
-
-3. If you are closing an issue please use one of the automatic closing words as
-   noted here: https://help.github.com/articles/closing-issues-using-keywords/
-
-4. If your pull request is not ready for review but you want to make use of the
-   continuous integration testing facilities please label it with `[WIP]`.
-
-5. If your pull request is ready to be reviewed without requiring additional
-   work on top of it, then remove the `[WIP]` label (if present) and replace
-   it with `[REVIEW]`. If assistance is required to complete the functionality,
-   for example when the C/C++ code of a feature is complete but Python bindings
-   are still required, then add the label `[HELP-REQ]` so that others can triage
-   and assist. The additional changes then can be implemented on top of the
-   same PR. If the assistance is done by members of the rapidsAI team, then no
-   additional actions are required by the creator of the original PR for this,
-   otherwise the original author of the PR needs to give permission to the
-   person(s) assisting to commit to their personal fork of the project. If that
-   doesn't happen then a new PR based on the code of the original PR can be
-   opened by the person assisting, which then will be the PR that will be
-   merged.
-
-6. Once all work has been done and review has taken place please do not add
-   features or make changes out of the scope of those requested by the reviewer
-   (doing this just add delays as already reviewed code ends up having to be
-   re-reviewed/it is hard to tell what is new etc!). Further, please do not
-   rebase your branch on main/force push/rewrite history, doing any of these
-   causes the context of any comments made by reviewers to be lost. If
-   conflicts occur against main they should be resolved by merging main
-   into the branch used for making the pull request.
-
 Many thanks in advance for your cooperation!
 
+Note: The pull request title will be included in the CHANGELOG.
 -->
+
+
+## Description
+<!-- Add brief description here -->
+
+## Issue
+<!-- Add closes #ISSUE_NUMBER here, this would close the issue once PR is merged, if there is no issue, please feel free to remove this section -->
+
+## Checklist
+
+- [ ] I am familiar with the [Contributing Guidelines](https://github.com/NVIDIA/cuopt/blob/HEAD/CONTRIBUTING.md).
+- Testing 
+   - [ ] New or existing tests cover these changes
+   - [ ] Added tests
+   - [ ] Created an issue to follow-up
+   - [ ] NA
+- Documentation
+   - [ ] The documentation is up to date with these changes
+   - [ ] Added new documentation 
+   - [ ] NA