Java Manual
This manual shares a lot with the JavaScript manual, in particular, it uses the exact same structure and some contents are duplicated.
### Tasks
- [x] Diff the original Java and JavaScript manuals to find content that could be interesting
- [x] Integrate the "disadvantages " in the intro. https://jgraph.github.io/mxgraph/docs/manual_javavis.html#1.2.1 seems to contains more information about "javascript"
Java Manual
This manual shares a lot with the JavaScript manual, in particular, it uses the exact same structure and some contents are duplicated.