Install command & repo URL typos in README / SKILL.md

[leekeithlee]

What I found

While setting up self-improving-agent for OpenClaw, two copy-paste hazards
showed up in the README and SKILL.md:

1. Repo URL typo (peterskoett → pskoett)

   • README and SKILL.md reference github.com/peterskoett/self-improving-agent
     and git clone https://github.com/peterskoett/self-improving-agent.git.
   • That owner handle redirects to pskoett/self-improving-agent on the web,
     so git clone from a fresh machine fails until the user notices.
   • Affects: README.md, self-improving-agent/SKILL.md (Installation section),
     and self-improving-agent/CHANGELOG.md.

2. clawdhub install self-improving-agent command

   • README and SKILL.md (and CHANGELOG) advertise clawdhub install ... as
     the recommended install path.
   • clawdhub is not on the install path here; the working commands are
     openclaw skills install self-improving-agent (built-in) or
     `clawhub install self-