Update PULL_REQUEST_TEMPLATE.md

At the request of the implementation team, this will provide a way to check/uncheck boxes without editing.

Signed-off-by: mkbreuning <97112931+mkbreuningIOHK@users.noreply.github.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,9 +6,9 @@ Link to any discussion, related issues and bug reports to give the context to he
 Link to existing ADR (Architecture Decision Record), if any. If relevant, describe other approaches explored and the selected approach. Documenting why the methods were not selected will create a knowledge base for future reference, helping prevent others from revisiting less optimal ideas.
 
 ### Checklist: 
-- [] My PR follows the [contribution guidelines](https://github.com/input-output-hk/atala-prism-wallet-sdk-ts/blob/master/CONTRIBUTING.md) of this project
-- [] My PR is free of third-party dependencies that don't comply with the [Allowlist](https://toc.hyperledger.org/governing-documents/allowed-third-party-license-policy.html#approved-licenses-for-allowlist)
-- [] I have commented my code, particularly in hard-to-understand areas
-- [] I have made corresponding changes to the documentation
-- [] I have added tests that prove my fix is effective or that my feature works
-- [] I have checked the PR title to follow the [conventional commit specification](https://www.conventionalcommits.org/en/v1.0.0/)
+- [ ] My PR follows the [contribution guidelines](https://github.com/input-output-hk/atala-prism-wallet-sdk-ts/blob/master/CONTRIBUTING.md) of this project
+- [ ] My PR is free of third-party dependencies that don't comply with the [Allowlist](https://toc.hyperledger.org/governing-documents/allowed-third-party-license-policy.html#approved-licenses-for-allowlist)
+- [ ] I have commented my code, particularly in hard-to-understand areas
+- [ ] I have made corresponding changes to the documentation
+- [ ] I have added tests that prove my fix is effective or that my feature works
+- [ ] I have checked the PR title to follow the [conventional commit specification](https://www.conventionalcommits.org/en/v1.0.0/)