Need end to end sample with knowledge base with a custom implementation for multimodal (custom lambda)

Customer Lambda will extract content from pdf, docs, ppts, excel, csv store to a vector database of serverless opensearch

No target file, test, or entry point is identified. Start by reviewing the repository's Amazon Bedrock examples and map the requested flow: customer Lambda extraction for PDF, docs, presentations, Excel, and CSV into a serverless OpenSearch vector database. Done would be a complete end-to-end multimodal knowledge-base sample.

Written by the indexing model from the issue text.