chore: add PULL_REQUEST_TEMPLATE (#1340)

Co-authored-by: th33xitus <domwil1091+github@gmail.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,51 @@
+<!--
+  For Work In Progress Pull Requests, please use the Draft PR feature,
+  see https://github.blog/2019-02-14-introducing-draft-pull-requests/ for further details.
+
+  For a timely review/response, please avoid force-pushing additional
+  commits if your PR already received reviews or comments.
+
+  We use squash-merge to merge PRs, so the commit history is clean, but we use the PR title as the commit message.
+  So we recommend you to use the PR title with conventional commits type prefixes. We use the following prefixes for the PR title:
+    - feat: A new feature
+    - fix: A bug fix
+    - docs: Documentation only changes
+    - style: Changes that do not affect the meaning of the code (white-space, formatting, etc)
+    - refactor: A code change that neither fixes a bug nor adds a feature
+    - perf: A code change that improves performance
+    - test: Adding missing tests or correcting existing tests
+    - chore: Changes to the build process or auxiliary tools and libraries such as documentation generation
+    - locale: Changes to the translations
+
+  You can found more information about Conventional Commits here: https://www.conventionalcommits.org/en/v1.0.0/.
+
+  Before submitting a Pull Request, please ensure you've done the following:
+  - 📖 Read the Mainsail Contributing Guidelines: https://github.com/mainsail-crew/mainsail/blob/HEAD/CONTRIBUTING.md#-submitting-a-pull-request-pr.
+  - 📖 Read the Mainsail Code of Conduct: https://github.com/mainsail-crew/mainsail/blob/HEAD/.github/CODE_OF_CONDUCT.md.
+  - 👷‍♀️ Create small PRs. In most cases, this will be possible.
+  - ✅ Provide tests for your changes.
+  - 📝 Use descriptive commit messages.
+  - 📗 Update any related documentation and include any relevant screenshots.
+-->
+
+## Description
+
+<!--
+Please do not leave this blank
+This PR [adds/removes/fixes/replaces] the [feature/bug/etc].
+-->
+
+## Related Tickets & Documents
+
+<!--
+Please use this format link issue numbers: Fixes #123
+https://docs.github.com/en/free-pro-team@latest/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword
+-->
+
+## Mobile & Desktop Screenshots/Recordings
+
+<!-- Visual changes require screenshots -->
+
+## [optional] Are there any post-deployment tasks we need to perform?
+
+<!-- note: PRs with deleted sections will be marked invalid -->