[SUPPORT]Problems with Hudi's version using LSM-tree

Hudi 0.14.1

This webpage "https://hudi.apache.org/docs/timeline/" indicates that Hudi has adopted the LSM-tree structure in its Timeline starting from version 0.14.1. However, upon inspecting the source code of Hudi version 0.14.1, I couldn't find any files with the letters "LSM" in their names, nor any content related to LSM. It seems that the utilization of LSM-tree in version 0.14.1 has not been implemented yet.

After extensive searching, I only found LSM-related usage in Release 1.0.0-beta1.

So are there some problems here? When will the official version of Hudi using LSM-tree be released?

In addition to that, I also want to ask if the addition of the source code related to the usage of LSM-tree in Hudi's timeline will be extensive. My undergraduate thesis topic is to modify the usage of LSM-tree in Hudi to improve its performance. I currently find the task quite challenging. Do the experts have any suggestions (such as how to efficiently read the source code related to LSM-tree in Hudi)?
I hope someone can answer. Thank you very much in advance!!!

Start with the Hudi timeline documentation URL and compare its 0.14.1 claims against the Hudi 0.14.1 source and the referenced 1.0.0-beta1 release. Done means establishing which version introduced the LSM-tree timeline and clarifying or correcting the documentation, with maintainer guidance on the relevant source area.

Written by the indexing model from the issue text.