Move skills into skills/ subdirectory

[lrhodin]

Summary

This restructures the repo to match the anthropic-skills layout:

pi-skills/
  README.md
  LICENSE
  skills/
    brave-search/
    browser-tools/
    ...

Problem

Previously, skill folders were at the repo root alongside README.md. This caused issues with pi-coding-agent (and likely other skill loaders) because they scan for .md files in the skills directory root and try to parse README.md as a skill definition, failing with:

[Skill conflicts]
  user ~/colter/skills/pi-skills/README.md
    description is required

Solution

By moving skills into a skills/ subdirectory, users configure their skill path to point at pi-skills/skills/ which contains only actual skill folders—no stray markdown files to confuse the scanner.

This matches how anthropic-skills is structured, where the README lives at the repo root and skills are nested one level deeper.

[llaughlin]

I'll second this 👍
I just tried running pi install git:github.com/badlogic/pi-skills and the skills aren't showing up. I'll need to add some kind of symlink in the meantime.