Soda contexture setup

[Ayushi2195]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespace from that line:

/kind new feature
/kind bug fix
/kind cleanup
/kind revert change
/kind design

/kind documentation

/kind enhancement

What this PR does / why we need it:
This PR adds a clear step-by-step guide to help set up and run Soda Contexture locally.

It includes:

• Prerequisites (Prometheus, Ollama) along with model suggestions
• Instructions for setting up the Python environment
• Steps for onboarding (such as generating embeddings)
• Configuration details for YAML files, .env variables, and DP logic
• Guidance on running the CLI and understanding query sets and output

This makes it much easier for first-time contributors to get started and run Soda Contexture without confusion.

Which issue(s) this PR fixes:
N/A (No related issue, as this PR only adds documentation)

Test Report Added?:

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespace from that line:

/kind TESTED

/kind NOT-TESTED

Test Report:

Special notes for your reviewer:
N/A