docs: evals for superpowers plugin

[christso]

Proposal

Add eval where you simply provide the issue.

#912

Compare superpowers and hivespec.

Which one consumers less tokens and completed in less time

Reproduction

Claude Opus 4.6 (200K context)

with baseline

• TODO

with superpowers:

• TODO

with hivespec

• devbox-2: /home/christso/.claude/projects/-home-christso-projects-agentv-allagents/e517648a-b812-42a9-aca8-e10d7418c2e9.jsonl