cleanup: remove outdated IPPL documentation

The IPPL documentation in ippl/doc is outdated and should be removed.

changed milestone to %OPAL 2.4.0

mentioned in merge request !263 (merged)

created merge request !263 (merged) to address this issue

@adelmann @gsell: Do we have the pdf of the IPPL documentation somewhere? If not, I would like to generate this first and put it on the wiki (for developers).

ah it actually compiles! I will put it on the wiki

@snuverink_j we have copies of the documentation in other repositories.

I am not aware of other IPPL documentation, is the documentation there less outdated?

@snuverink_j : no. Anyway the LaTeX files are still available in all branches before 2.4.

ok, in any case I have also put the PDF here: https://gitlab.psi.ch/OPAL/src/wikis/For-Developers/ippl_user_guide.pdf, with a link to it on home.md

closed via merge request !263 (merged)

mentioned in commit 28fe7987