Add issue and pr templates (#509)

* feat: add issue templates

* fix: adjust wording

* fix: add nix note

Author: drbh

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,56 @@
+name: Bug Report
+description: Report a bug or unexpected behavior
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for reporting a bug! Please fill in the details below.
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: A clear description of the bug.
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Steps to reproduce
+      description: Minimal code or steps to reproduce the issue.
+      placeholder: |
+        ```python
+        import kernels
+        ...
+        ```
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+      description: What you expected to happen.
+    validations:
+      required: true
+  - type: textarea
+    id: environment
+    attributes:
+      label: Environment
+      description: Please provide version info.
+      placeholder: |
+        - kernels version:
+        - Python version:
+        - PyTorch version:
+        - CUDA version:
+        - GPU model:
+        - OS:
+        - If using the Nix builder, output of `nix-shell -p nix-info --run "nix-info -m"`:
+    validations:
+      required: true
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional context
+      description: Any other context, logs, or screenshots.
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,46 @@
+name: Feature Request
+description: Propose a new feature or improvement
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for your interest in contributing! Please describe what you'd like to
+        see and why. If you're planning to submit a PR, **please open this issue first**
+        and wait for feedback before starting work - this helps us align on approach and
+        avoids duplicate or unnecessary effort.
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: A clear description of the feature you'd like.
+    validations:
+      required: true
+  - type: textarea
+    id: motivation
+    attributes:
+      label: Motivation
+      description: Why is this feature needed? What problem does it solve? What is your use case?
+    validations:
+      required: true
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Proposed approach
+      description: If you have an idea of how this could be implemented, describe it here. This is especially helpful if you plan to submit a PR.
+    validations:
+      required: false
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives considered
+      description: Any alternative solutions or workarounds you've considered.
+    validations:
+      required: false
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional context
+      description: Any other context, references, or screenshots.
+    validations:
+      required: false

.github/pull_request_template.md

@@ -0,0 +1,37 @@
+## Important: Read before submitting
+
+> **New contributors:** Please open or comment on an issue **before** submitting a
+> PR to discuss the change you'd like to make. This helps us align on approach and
+> avoids wasted effort on changes we may not be able to merge.
+
+## Related issue
+
+<!-- Link the issue this PR addresses. Every PR should have a corresponding issue. -->
+
+Closes #
+
+## What does this PR do?
+
+<!-- A brief description of the changes. -->
+
+## Motivation
+
+<!-- Why is this change needed? What context is important for reviewers? -->
+
+## Changes
+
+<!-- Bulleted list of key changes. -->
+
+-
+
+## Testing
+
+<!-- How were these changes tested? Include commands, test output, or benchmarks. -->
+
+-
+
+## Checklist
+
+- [ ] This PR is linked to an issue that was discussed and approved
+- [ ] I have tested these changes locally
+- [ ] New/changed functionality has test coverage