docs: add tutorials and documentation for point cloud data

## Summary

The Sedona DB website currently lacks tutorials and documentation for working with point cloud data (e.g., LAS/LAZ files). We should add user-facing materials that show how to read, process, and analyze point cloud datasets with Sedona DB.

## Motivation

Point cloud support is a differentiating capability of Sedona DB, but new users have little guidance on how to use it. Adding tutorials and reference docs will lower the barrier to entry and help users discover the available functionality.

## Proposed content

- **Getting started tutorial**: reading a LAS/LAZ file, inspecting the schema, and previewing points
- **Working with point cloud columns**: available data types, projections, and column semantics
- **Common workflows**: filtering by attribute (classification, intensity, return number), spatial filtering, aggregation
- **Interop examples**: combining point cloud data with vector/raster data in a single query
- **Reference page**: list of supported point cloud functions and readers with examples

## Scope

- New pages under the Sedona DB docs site covering the topics above
- Example notebooks or runnable snippets where appropriate
- Cross-links from the main docs landing page so the content is discoverable

## Out of scope

- New point cloud functionality (this issue is docs-only)

Start by surveying the existing Sedona DB docs structure and point-cloud readers and functions to identify appropriate page locations and runnable examples. Done means the proposed tutorials, column and workflow guidance, interoperability examples, reference page, and landing-page links are published and usable.

Written by the indexing model from the issue text.