Upload knowledge-base document

curl --request POST \
  --url https://api.wacht.dev/ai/knowledge-bases/{kb_id}/documents \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file' \
  --form 'title=<string>' \
  --form 'description=<string>'

{
  "id": "<string>",
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "title": "<string>",
  "description": "<string>",
  "file_name": "<string>",
  "file_size": 123,
  "file_type": "<string>",
  "storage_object_key": "<string>",
  "knowledge_base_id": "<string>",
  "processing_metadata": {}
}