Add required bug report issue form (#1333)

# Summary

Adds a bug-report form so reports include the details needed to
reproduce a problem.

# Description of the change

Requires a complete minimal reproducer, full error messages or observed
output, and environment details. The form also asks for expected versus
actual behavior and explains how to collect PyTorch environment
information.

Targets the default branch because GitHub loads issue forms from there.

Fixes #1248.

# Validation

Validated the form against the issue-form JSON schema and checked that
all four required fields start empty. Confirmed that the suggested
environment command runs locally. GitHub's rendered form still needs
verification after merging.

---------

Signed-off-by: AKILSURYA SIVAKUMAR <akilsurya20399@gmail.com>
Signed-off-by: RBendias <rbendias@nvidia.com>
Co-authored-by: RBendias <rbendias@nvidia.com>

Author: AkilsuryaS

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,59 @@
+name: 🐛 Bug Report
+description: Create a report to help us reproduce and fix the bug
+labels: [bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to report this problem! Issues that do not follow the checklist below may be closed.
+  - type: checkboxes
+    attributes:
+      label: Checklist
+      description: Please confirm the following before submitting.
+      options:
+        - label: I have reviewed the [contributing guidelines](https://github.com/Nvidia/structured-data-models/blob/main/CONTRIBUTING.md) and [AI policy](https://github.com/Nvidia/structured-data-models/blob/main/AGENTS.md#ai-policy).
+          required: true
+        - label: I have searched the [existing and past issues](https://github.com/Nvidia/structured-data-models/issues?q=is%3Aissue+sort%3Acreated-desc+) and this bug has not been reported yet.
+          required: true
+        - label: I have checked whether the bug also reproduces on the latest `main`.
+  - type: textarea
+    attributes:
+      label: 🐛 Describe the bug
+      description: A clear and concise description of what the bug is, and what you expected to happen instead.
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Reproducible code example
+      description: |
+        A minimal, self-contained script that we can copy and run to reproduce the bug. Please trim down any irrelevant code.
+        Use synthetic or publicly available data, and include any required checkpoint name or revision.
+      render: python
+      placeholder: |
+        # All necessary imports at the beginning
+        import torch
+        import sdm
+
+        # A succinct reproducing example trimmed down to the essential parts:
+        ...
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Error message or observed output
+      description: The **full** traceback of the exception, or the output that shows the incorrect behavior.
+      render: text
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Versions
+      description: |
+        Your structured-data-models version or Git commit, how you installed it (e.g. pip, editable source checkout, or container image and tag), and the output of `python -m torch.utils.collect_env`.
+      render: text
+    validations:
+      required: true
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for contributing 🎉!