The most significant changes include the emphasis on the requirement …

…for Java 21 in the README files, the reformatting of the supported Spine versions into a table, the addition of a "Build" section in the README-Eng.md file, and the correction of a repetition error in the README.md file.

1. The requirement for Java 21 has been highlighted in both README-Eng.md and README.md files by making it bold. This change emphasizes the importance of having the correct Java version for the project.

2. The list of supported Spine versions in the README files has been replaced with a table. This change improves readability and provides a clear overview of the support status for different Spine versions. The table indicates that Spine 1.x is not supported and the support for Spine 2.x to Spine 3.3 is uncertain.

3. A new "Build" section has been added to the README-Eng.md file. This section provides instructions on how to rewrite `MANIFEST.MF` of `org.lwjgl.lwjgl:lwjgl` to make `Sealed: false`. This change is crucial for the build process of the project.

4. A repetition error in the README.md file has been corrected. The requirement for Java was mistakenly repeated three times as "Java 21 21 21". This change ensures the accuracy of the project's requirements.

References to the code changes can be found in the commit history of the project.