Create pull request template for contributions

Added a pull request template to guide contributors in the SharpEmu Emulator Project.

.github/pull_request_template.md

@@ -0,0 +1,20 @@
+<!--
+Copyright (C) 2026 SharpEmu Emulator Project
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
+## Before submitting
+
+Please read our contribution guidelines before opening a pull request:
+
+➡️ [**CONTRIBUTING.md**](CONTRIBUTING.md)
+
+By opening this pull request, you confirm that you have read and agree to follow the contribution guidelines.
+
+## Checklist
+By submitting this PR, you confirm that:
+
+- [ ] I have read `CONTRIBUTING.md`.
+- [ ] I tested my changes.
+- [ ] I wrote this description myself and did not copy AI-generated explanations.
+- [ ] I listed the game(s) I tested, if applicable.