add: PR template

Author: kozistr

.github/pull_request_template.md

@@ -0,0 +1,29 @@
+---
+Remove this part when you open the PR
+
+Here's a checklist before opening the Pull Request!
+
+1. PR Title convention : [Type of PR] [Summary] (e.g. [Feature] Implement AdamP optimizer)
+2. Attach `as much information as possible you can`. It helps the reviewers a lot :)
+3. Make sure the code is perfectly `runnable & compatible`.
+4. If your PR is not ready yet, make your `PR` to `Draft PR`.
+5. Make sure `make check` before opening the `PR`.
+---
+
+## Problem (Why?)
+
+_What problem are you trying to solve?_
+
+## Solution (What/How?)
+
+_How did you solve the problem? Please provide a complete description and explanation!_
+
+_It'd be appreciated to attach Change Logs or `Notion`, `Jira` link. If you train a model, then attach `Tensorboard` or `WanDB` reports with accessible URLs_
+
+## Other changes (bug fixes, small refactors)
+
+_Are there any small changes?_
+
+## Notes
+
+_Please note any questions, helps or contexts what maintainer(s) should know_