P0 follow-up for EA-471. Updates plugin-dev teaching materials to stop
recommending the commands/ directory layout for new plugins:
- command-development/SKILL.md: add legacy banner at top pointing to
skills/ format
- create-plugin.md: update scaffolding to create skills/<name>/SKILL.md
instead of commands/; mark commands/ as acceptable legacy alternative;
update all examples, tables, and testing instructions
- example-plugin: migrate example-command to skills/example-command/SKILL.md;
keep commands/example-command.md with a legacy-format note; update README
to reflect new preferred structure
Both formats remain loaded identically — this is a documentation change only.
Refs: anthropics/apps#26827
Co-authored-by: Henry Shi <henrys@anthropic.com>
