docs: add new PR template to standardise contributions

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,88 @@
+<!--
+  Thanks for contributing to gh-skyline! Please fill out the sections below
+  to help reviewers understand and validate your change.
+-->
+
+## Description
+
+<!-- A clear and concise description of what this PR does and why. -->
+
+## Related issues
+
+<!-- Link any related issues, e.g. "Closes #123" or "Refs #456". -->
+
+Closes #
+
+## Type of change
+
+<!-- Check all that apply by replacing [ ] with [x]. -->
+
+- [ ] Bug fix (non-breaking change which fixes an issue)
+- [ ] New feature (non-breaking change which adds functionality)
+- [ ] Breaking change (fix or feature that would change existing behavior)
+- [ ] Refactor / code cleanup (no functional change)
+- [ ] Documentation update
+- [ ] CI / build / tooling change
+- [ ] Dependency update
+
+## Areas affected
+
+<!-- Check all that apply. -->
+
+- [ ] CLI commands / flags (`cmd/`)
+- [ ] GitHub API client (`internal/github/`)
+- [ ] STL generation / geometry (`internal/stl/`)
+- [ ] ASCII art rendering (`internal/ascii/`)
+- [ ] Logger / errors / utils (`internal/logger`, `internal/errors`, `internal/utils`)
+- [ ] Types (`internal/types/`)
+- [ ] Tests / fixtures / mocks (`internal/testutil/`)
+- [ ] Documentation (README, CONTRIBUTING, etc.)
+- [ ] CI workflows / linters (`.github/`)
+
+## How has this been tested?
+
+<!--
+  Describe the testing you performed. At minimum, run:
+
+    go test ./...
+    golangci-lint run
+
+  If your change affects STL output, please verify the file is valid
+  (e.g. opens correctly in a 3D viewer / slicer) and remains float32
+  to comply with the binary STL format.
+-->
+
+- [ ] `go test ./...` passes locally
+- [ ] `golangci-lint run` passes locally
+- [ ] Manually ran the extension locally (e.g. `go run main.go --user <user> --year <year>` or `./rebuild.sh && gh skyline ...`)
+- [ ] Verified the generated STL opens in a 3D viewer / slicer (if applicable)
+- [ ] Added or updated unit tests for new / changed behavior
+
+### Commands run
+
+```bash
+# Paste the commands you ran and a brief summary of the output
+go test ./...
+```
+
+## Screenshots / output
+
+<!--
+  If your change affects user-facing output, attach screenshots of:
+    - the ASCII art preview, and/or
+    - the rendered STL (3D viewer screenshot), and/or
+    - relevant terminal output.
+-->
+
+## Checklist
+
+- [ ] My code follows the style of this project (see [`.github/linters/.golangci.yml`](.github/linters/.golangci.yml))
+- [ ] I have added GoDoc comments for any new exported packages, functions, types, or constants
+- [ ] Functions are focused and reasonably sized (generally under 50 lines)
+- [ ] Final STL output uses `float32` to adhere to the STL format (if applicable)
+- [ ] I have updated the README / docs where relevant (new flags, behavior changes, etc.)
+- [ ] I have read the [Contributing guide](../CONTRIBUTING.md) and [Code of Conduct](../CODE_OF_CONDUCT.md)
+
+## Additional notes for reviewers
+
+<!-- Anything else reviewers should know: trade-offs, follow-ups, open questions, etc. -->