docs: fix plugin install commands in README

refactor: decompose workflow-optimizer into progressive disclosure structure

feat: add skill-advisor skill and rename to claude-optimizer (v1.2.0)

chore: rename plugin name to workflow-optimizer

refactor: align skill with Claude Code official architecture (v1.1.0)

chore: rename skill to claude-workflow-optimizer

feat: initial release — workflow-optimizer plugin v1.0.0