Docs: Update pull_request_template.md (#2928)

.github/pull_request_template.md

@@ -10,6 +10,6 @@
 
 ## Checklist
 
-- [ ] Format your code according to the [Contributor Guide](https://github.com/sgl-project/sglang/blob/main/docs/references/contribution_guide.md).
-- [ ] Add unit tests as outlined in the [Contributor Guide](https://github.com/sgl-project/sglang/blob/main/docs/references/contribution_guide.md).
-- [ ] Update documentation as needed, including docstrings or example tutorials.
+- [ ] Format your code according to the [Code Formatting with Pre-Commit](https://docs.sglang.ai/references/contribution_guide.html#code-formatting-with-pre-commit).
+- [ ] Add unit tests as outlined in the [Running Unit Tests](https://docs.sglang.ai/references/contribution_guide.html#running-unit-tests-adding-to-ci).
+- [ ] Update documentation / docstrings / example tutorials as needed, according to [Writing Documentation](https://docs.sglang.ai/references/contribution_guide.html#writing-documentation-running-docs-ci).