[R package] Review package DESCRIPTION, development and release process

[tbouffard]

release process

For now, we have remaining branches and git tags
we should be able to only keep the git tags as the package installation using install_github can use a git tag with the ref parameter (https://www.rdocumentation.org/packages/remotes/versions/2.4.0/topics/install_github)
If so, update the install procedure in the README

DESCRIPTION

The version, title, description and license are not or incompletely set.
license should be License: Apache License (== 2)

Notice that due to the current release process, the DESCRIPTION file is never updated in the master branch

development

The jar file is not available in the master branch because we don't want to mess the repo.
We should explain how to get it when developing the package. There is no git ignore for the jar that MUST not be commited during dev (only during release): error prone
Makefile: review PACKAGE_NAME=rJavaPackageExample

As for the release, run make install from the R/bpmnLayoutGeneratoR folder