Add PR description lint

[disa6302]

Issue #, if available:

What was changed?

• Add PR template check to CI and a PR template for this repo.

Why was it changed?

• To ensure that every PR that is opened has a clear description of the changes.

How was it changed?

• Created a PR template
• Created a CI job to run the description checker

What testing was done for the changes?

• The same template exists in WebRTC SDK which has been working fine for the past few months.
• CI job in this PR to verify this description.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (ffef12d) 80.34% compared to head (528c843) 80.34%.

:exclamation: Current head 528c843 differs from pull request most recent head 250ffc9. Consider uploading reports for the commit 250ffc9 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #248 +/- ## ======================================== Coverage 80.34% 80.34% ======================================== Files 53 53 Lines 10808 10808 ======================================== Hits 8684 8684 Misses 2124 2124 ```

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