Create PULL_REQUEST_TEMPLATE.md

Created by: PuneetGopinath

Thanks for contributing to bootstrap! Plz check the below things before submitting your pr:

• I have read and followed the contributing guidelines

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Closes #

I just added a pull request template, many people feel lazy typing the body of the pr (Including me!). So i added a pr template

.github/PULL_REQUEST_TEMPLATE.md

+# Thanks for contributing to bootstrap! Plz check the below things before submitting your pr:
+
+- [ ] I have read and followed the [contributing guidelines](https://github.com/twbs/bootstrap/blob/main/.github/CONTRIBUTING.md)
+
+---------------------------------------------------------------------
+
+<!-- If this pr, solves/fixes a issue
+Mention the issue number below -->
+Closes #
+
+> Describe your changes here, e.g. Updated the getting-started guide in docs