Update PULL_REQUEST_TEMPLATE.md

Co-authored-by: Ruslan <ruslanpopov1512@gmail.com>
Co-authored-by: Subhramit Basu Bhowmick <74734844+subhramit@users.noreply.github.com>
Co-authored-by: Carl Christian Snethlage <50491877+calixtus@users.noreply.github.com>
Co-authored-by: ThiloteE <73715071+ThiloteE@users.noreply.github.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -13,10 +13,10 @@ Don't reference an issue in the PR title because GitHub does not support auto-li
 - [x] done; [ ] not done / not applicable
 -->
 
+- [x] I own the copyright of the code submitted and I licence it under the [MIT license](https://github.com/JabRef/jabref/blob/main/LICENSE)
 - [ ] Change in `CHANGELOG.md` described in a way that is understandable for the average user (if applicable)
 - [ ] Tests created for changes (if applicable)
 - [ ] Manually tested changed features in running JabRef (always required)
-- [ ] I own the copyright of the code submitted and I licence it under the MIT license
 - [ ] Screenshots added in PR description (for UI changes)
 - [ ] [Checked developer's documentation](https://devdocs.jabref.org/): Is the information available and up to date? If not, I outlined it in this pull request.
 - [ ] [Checked documentation](https://docs.jabref.org/): Is the information available and up to date? If not, I created an issue at <https://github.com/JabRef/user-documentation/issues> or, even better, I submitted a pull request to the documentation repository.