Release 0.6.21 (#1329)

.changeset/clever-hats-change.md

.changeset/soft-papayas-care.md

apps/docs/CHANGELOG.md

apps/docs/package.json

packages/autotool/CHANGELOG.md

packages/autotool/examples/01_node/CHANGELOG.md

packages/autotool/examples/01_node/package.json

packages/autotool/examples/02_nextjs/CHANGELOG.md

packages/autotool/examples/02_nextjs/package.json

packages/autotool/package.json

packages/experimental/CHANGELOG.md

packages/experimental/package.json

packages/llamaindex/CHANGELOG.md

...maindex/e2e/examples/cloudflare-worker-agent/CHANGELOG.md

...maindex/e2e/examples/cloudflare-worker-agent/package.json

packages/llamaindex/e2e/examples/nextjs-agent/CHANGELOG.md

packages/llamaindex/e2e/examples/nextjs-agent/package.json

.../llamaindex/e2e/examples/nextjs-edge-runtime/CHANGELOG.md

.../llamaindex/e2e/examples/nextjs-edge-runtime/package.json

.../llamaindex/e2e/examples/nextjs-node-runtime/CHANGELOG.md