add pr template

Signed-off-by: chang-ning <spiderpower02@gmail.com>

Author: crazyguitar

.github/pull_request_template.md

@@ -0,0 +1,24 @@
+## Purpose
+
+<!-- Explain what this PR does and why. Link related issues, e.g. "Closes #123". -->
+
+## Test Plan
+
+<!-- How did you test this? Commands, hardware/NIC used, or steps to reproduce. -->
+
+## Test Result
+
+<!-- Paste the outcome: command output, before/after counters, screenshots of the TUI, etc. -->
+
+---
+
+<details>
+<summary>Checklist</summary>
+
+- [ ] `cargo fmt --check` passes
+- [ ] `cargo clippy -- -D warnings` passes
+- [ ] `cargo test` passes
+- [ ] Tested on RDMA-capable hardware (or explained why not in the Test Plan)
+- [ ] Docs/README updated if behavior or flags changed
+
+</details>