Add Sphinx Documentation

[OleSeifert]

This pull request introduces comprehensive documentation for the backend system, including a detailed system architecture overview, API endpoints, and associated models. Additionally, it provides supporting files for building and generating documentation using Sphinx. The most important changes are grouped into themes below:

Documentation for System Architecture and Backend Components:

• Added docs/source/architecture.rst to explain the backend architecture, interaction with the Celonis platform, and key components like conformance checking techniques, PQL queries, and API structure.

Auto-Generated API Documentation:

• Created docs/source/autoapi/backend/api/celonis/index.rst to document the backend.api.celonis module, including the CelonisSettings class and get_celonis_connection function.
• Added docs/source/autoapi/backend/api/log/index.rst to document the backend.api.log module, including routes for uploading logs and committing them to the Celonis platform.
• Added docs/source/autoapi/backend/api/jobs/index.rst to describe the backend.api.jobs module, including job-related routes and helper functions.

Supporting Files for Sphinx Documentation:

• Added docs/Makefile to define commands for generating documentation using Sphinx, including targets for building and generating .rst API files.
• Added docs/make.bat to provide equivalent functionality for Windows environments.

These changes enhance the project's documentation, making it easier for developers to understand the backend architecture and interact with its APIs.

Important files

The only important files are the .rst files in the docs/source directory, as these are not automatically generated.

[samadrita-saha]

LGTM. Nice work! :)