docs: add note about demos on PRs

[Patrick-Erichsen]

Summary by cubic

Added a note to the PR template and contributing guide asking for a short screen recording when submitting new features, to make reviews easier.

[netlify]

❌ Deploy Preview for continuedev failed. Why did it fail? →

Name	Link
🔨 Latest commit	653ed97
🔍 Latest deploy log	https://app.netlify.com/projects/continuedev/deploys/68747efb23cab8000892b167

[cubic-dev-ai]

cubic reviewed 2 files and found no issues. Review PR in cubic.dev.

[github-actions]

⚠️ Conventional Commit Format

Your commit messages don't follow the conventional commit format, but this won't block your PR from being merged. We recommend downloading this extension if you are using VS Code.

Expected Format:

<type>[optional scope]: <description>

[optional body]

[optional footer(s)]

Examples:

• feat: add changelog generation support
• fix: resolve login redirect issue
• docs: update README with new instructions
• chore: update dependencies

Valid Types:

feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert

This helps with:

• 📝 Automatic changelog generation
• 🚀 Automated semantic versioning
• 📊 Better project history tracking

This is a non-blocking warning - your PR can still be merged without fixing this.