[Documentation]: rvload2 file description is outdated

The documentation in Chapter 9 (https://openrv.readthedocs.io/en/latest/rv-manuals/rv-reference-manual/rv-reference-manual-chapter-nine.html#package-management-configuration-files) is describing the rvload2 file that RV uses to keep track of loaded packages.

It describes version 3 of the file but currently OpenRV creates version 4 files which has additional fields per line for the package's minimum supported RV + OpenRV versions as well as an optional field when a mode is depending on other modes (the "requires" key in the PACKAGE file).

Example from documentation:
```
3
window_title,window_title.zip,nil,nil,nil,true,true,false
```

Current format that I am seeing (OpenRV 3.1.0)
```
4
mymode,mymode-1.0.rvpkg,nil,nil,nil,true,true,3.12.9,true,1.0.0,othermode
```

Open the Chapter 9 package management configuration files section linked in the issue and compare its rvload2 description with the version 4 example provided. Update the documentation to describe the newer fields and format, then verify that the example and explanatory text match the current OpenRV format.

Written by the indexing model from the issue text.