Suggestions for small improvements

[felixhekhorn]

• Improve Readme of pineappl at PyPI - it is currently empty; e.g. mirror the main one
• pineappl at PyPI is currently listed as "Development Status: 4 - Beta" - that's wrong
• maybe improve the Readme of pineappl-cli at PyPI - which is mirroring the local Readme. E.g.
  • mention activated features
  • point to CLI tutorial
• point the Rust badge on the main Readme to https://github.com/NNPDF/pineappl/actions?query=workflow%3ARust+branch%3Amaster instead (since it is currently show the failing state the most recent run which is irrelevant to the main project) 7542df5
• mg5 tutorial is outdated - mentioned bash script now contains version number (and there are two of them)
• Automatically install the C++ header file along the C one using build.rs
• Keep track of codes and tools using PineAPPL: it would be useful to list somewhere all the tools and codes that use PineAPPL for our own and other people's references (for e.g. I just noticed this morning that there is a POWHEG interface for DIS events)

[Radonirinaunimi]

Thanks @felixhekhorn! I fully agree that these should be addressed and I added some points to your list. Some of them were already on my TODO list but so far haven't had the time to address them.

[felixhekhorn]

I wanted to ask live, but then forgot again 🙃

• mention activated features

what I mean here is: which features are already active in the PyPI version? This is relevant e.g. for NNPDF/pinecards#192 - i.e. can we just rely on the PyPI version to have e.g. the fastnlo feature?

This is different from improving https://github.com/NNPDF/pineappl/blob/master/pineappl_cli/README.md on its own. Eventually, on PyPI we want both things if possible.

[felixhekhorn]

Another minor follow-up: after the recent CLI wheels workflow rework (#375 #376 ): the dependency management between Linux and MacOS is out of sync. That is the Linux dependency management

pineappl/maintainer/install-cli-dependencies.sh

Line 3 in 4753ba6

APPLGRID_V=1.6.36

pins e.g. APPL, where as the MacOS version

pineappl/.github/workflows/release-cli-wheels.yaml

Line 136 in 4753ba6

brew install --only-dependencies --without-hoppet --without-lhapdf --without-root applgrid

does not. Most likely this will not cause harm in the short run, but it is an inconsistency and might eventually. An easy solution would be to pin the version in the workflow file and then pass them either down to the linux install script or use them for MacOS. This discussion might well be completely void if brew only supports the most recent version (or not the one we want) (which I don't know since I don't use Mac 🙃 ).