feat: Add feature request template proposal

As decided in the related discussion: we will start with 3 simple issue
templates and iterate from there.

This one introduces the feature request template.

Refs: [discussion](https://github.com/nishanb/CK-X/discussions/15_)

.github/ISSUE_TEMPLATE/feature-request.md

@@ -0,0 +1,55 @@
+---
+name: "✨ Feature Request"
+about: Suggest an improvement or new feature for CK-X Simulator
+title: "[Feature] <short description>"
+labels: enhancement
+assignees: ''
+
+---
+
+## Describe the feature
+
+<!-- A clear and concise description of the feature or improvement.
+
+What would this feature do?
+
+Why is it useful or necessary for the user?
+
+-->
+
+## Motivation
+
+<!-- Explain *why* you’re proposing this.
+
+- What problem does it solve?
+- What benefit would it bring to users or developers?
+- Is this inspired by a real use case?
+
+-->
+
+## Proposed Solution
+
+<!-- Describe how you imagine the feature should work.
+
+You can include:
+
+- A workflow
+- Example UI mockups or commands
+- Integration points
+-->
+
+## Alternatives considered
+
+<!-- Have you considered any alternative approaches?
+
+Why did you choose this one?
+
+-->
+
+## Additional context
+
+<!-- Add any other context or supporting info (e.g. links, diagrams, references). -->
+
+## Related Issues
+
+<!-- Link to any related issues or pull requests, if applicable. -->