[Dev] Enhance examples on README

[LeiWang1999]

This pull request includes updates to the README.md file for the tile-lang project. The changes primarily focus on adding new information and refining existing examples to improve clarity and usability.

Documentation Updates:

• Added a "Latest News" section to announce the open-source release of tile-lang.

Example Code Refinements:

• Removed the "Basic GEMM Example" and merged it with the "Enhanced Example with Annotations" to provide a more comprehensive and annotated example of matrix multiplication using tile-lang.
• Added optional layout optimizations and rasterization annotations to the GEMM example for better L2 cache locality and performance.