Improve onboarding, positioning, and demos for new OpenCode skill users

[antongulin]

Prompted by discussion: #12

A user asked why the project is not getting more attention and guessed many people may still be using Claude Code. That seems like a useful signal: the project may need clearer positioning, faster first-run proof, and stronger examples.

Recommended improvements:

• Add a README section: “If you use Claude Code skill-creator, this is the OpenCode equivalent.”
• Add a small feature comparison table covering Claude Code skill-creator vs this OpenCode skill/plugin.
• Add a 2-minute demo GIF or video showing install -> create skill -> run evals -> open review viewer -> optimize description.
• Add 2-3 example skills built with this tool, such as Docker Compose helper, API docs writer, or PR review checklist.
• Add a copy-paste “first thing to ask after install” prompt near the top of the README.
• Create or pin a Discussion for “Show us the skills you created” to collect real usage stories.
• Position the project as early OpenCode ecosystem infrastructure: making skills reliable with evals instead of prompt vibes.

Acceptance ideas:

• README clearly explains who this is for and how it compares to Claude Code skill-creator.
• A new user can understand the value in under 60 seconds.
• At least one example skill or demo path is linked from the README.
• Discussion 怎么热度这么低 #12 has a friendly reply inviting feedback from early users.