serviette: universal RAG indexer and server

[zxqfd555]

Introduction

To contribute code to the Pathway Live Data Framework project, start by discussing your proposed changes on Discord or by filing an issue.
Once approved, follow the fork + pull request model against the main branch, ensuring you've signed the contributor license agreement.

Context

How has this been tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature or improvement (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Related issue(s):

Checklist:

• My code follows the code style of this project,
• My change requires a change to the documentation,
• I described the modification in the CHANGELOG.md file.

[olruas]

LGTM