[DOCS] Add blog post on the raster data source tiling reader

[jiayuasu]

Did you read the Contributor Guide?

• Yes, I have read the Contributor Rules and Contributor Development Guide

Is this PR related to a ticket?

• No: this is a documentation update. The PR name follows the format [DOCS] my subject

What changes were proposed in this PR?

Adds a blog post, "Open Huge GeoTIFFs Without the 2 GB Wall", introducing the raster data source that tiles a GeoTIFF into one row per tile on read (1.9.0). The post uses a 3.5 GB AlphaEarth Foundations embedding scene (8192×8192, 64 bands, COG with 1024×1024 internal tiles) as the running example and covers:

• why a whole-file read hits Spark's per-record ceiling, and how per-tile reading avoids it;
• the retile / tileWidth / tileHeight / padWithNoData options and directory globbing (recursiveFileLookup, pathGlobFilter);
• inspecting the tiled DataFrame and running cross-tile zonal statistics.

New files:

• docs/blog/posts/raster-tiling-reader.md
• docs/blog/posts/raster-tiling-reader-cover.svg (hand-authored SVG cover)

How was this patch tested?

Documentation-only change. The code snippets were verified locally by loading a real 3.5 GB GeoTIFF through sedona.read.format("raster") and running the inspection and zonal-statistics queries shown in the post: the file split into 64 tiles (8×8) of 1024×1024×64 bands each, and the tiling-aware zonal-stats roll-up (SUM(sum)/SUM(count)) counted exactly the expected number of pixels across the overlapping tiles. The page renders in the mkdocs blog and passes the repo's markdownlint/codespell pre-commit hooks.

Did this PR include necessary documentation updates?

• Yes, I have updated the documentation.