docs: add getting started section with maven dependency info
authorSvjatoslav Agejenko <svjatoslav@svjatoslav.eu>
Sun, 5 Apr 2026 00:03:28 +0000 (03:03 +0300)
committerSvjatoslav Agejenko <svjatoslav@svjatoslav.eu>
Sun, 5 Apr 2026 00:03:28 +0000 (03:03 +0300)
commit2f6d4d86c89a700fc70e9d7c38d37134ffb2fed2
treef4307ecee4d72195490d9c3a973e7826fa28aa2a
parent8de8977214ce78b58f05ccfc98a462109ff572e7
docs: add getting started section with maven dependency info

- Add new "How take engine into use" section with Maven dependency
  coordinates and repository configuration
- Document Java 21+ requirement
- Consolidate getting started links (demos, JavaDoc, class diagrams)
- Remove redundant "Understanding the Sixth 3D source code" section
doc/index.org