docs(getting-started): add delta-rs (Rust/Python) quickstart + links

[Username46786]

What changed?

• Added a new section "Use Delta Lake without Spark (delta-rs: Rust & Python)" to the Getting Started page.
• Provides links to delta-rs documentation (Rust) and the Python deltalake package on PyPI.
• Includes a minimal Python quickstart snippet (write_deltalake, DeltaTable) that new users can run locally.
• Helps surface delta-rs usage as an alternative to Spark for smaller-scale or embedded workflows.

Why?

• Addresses the need to better surface delta-rs docs (see Add link to delta-rs docs #361).
• Many new users want to try Delta Lake from Python or Rust without needing Spark.
• Adds clarity and improves discoverability of delta-rs resources.

Preview impact

• Visitors to Getting Started will now see non-Spark options alongside Spark setup.
• Direct links to delta-rs docs and PyPI help beginners find the right resources faster.