Use "Issue Form" for issue templates

## Problem

The current issue template for "Pitch" may be intimidating and scare away good feature ideas.

## Solution

The Issue Form feature provided by GitHub creates an interactive form that guide the user fill out the pitch:

https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository#creating-issue-forms

Examples:

- https://github.com/vitejs/vite/issues/new?assignees=&labels=enhancement%3A+pending+triage&template=feature_request.yml
- https://github.com/storybookjs/storybook/issues/new?assignees=&labels=needs+triage%2Cfeature+request&template=feature_request.yml&title=%5BFeature+Request%5D%3A

Start by inspecting the repository's current "Pitch" issue template and compare it with GitHub's issue-form documentation and the linked Vite and Storybook examples. Done means the Pitch template is an interactive GitHub Issue Form that guides feature submissions without intimidating contributors.

Written by the indexing model from the issue text.