Move the skill from the shared skills/servicebridge-node to node/skill so it
lives with the SDK it documents (future Go/Python SDKs get their own
node/skill sibling). Add skill to the npm files whitelist so the tarball
carries it — npm i service-bridge now brings the skill, copyable from
node_modules/service-bridge/skill. Update README and docs install paths; bump
to 2.0.0-alpha.2 to publish the bundled skill.