feat: support uploading pdf, docx, txt (#140)

.changeset/late-weeks-sneeze.md

helpers/index.ts

helpers/python.ts

helpers/typescript.ts

questions.ts

templates/components/engines/python/agent/__init__.py

templates/components/engines/python/agent/tools/img_gen.py

...ates/components/engines/python/agent/tools/interpreter.py

templates/components/engines/python/chat/__init__.py

templates/components/engines/typescript/agent/chat.ts

...ates/components/engines/typescript/agent/tools/img-gen.ts

.../components/engines/typescript/agent/tools/interpreter.ts

templates/components/engines/typescript/chat/chat.ts

...s/components/llamaindex/typescript/documents/documents.ts

...components/llamaindex/typescript/streaming/annotations.ts

...ates/components/llamaindex/typescript/streaming/events.ts

...ates/components/llamaindex/typescript/streaming/stream.ts

templates/components/ui/html/chat/hooks/use-config.ts

templates/components/vectordbs/python/none/generate.py

templates/types/streaming/express/gitignore