Decorrelation models

Bugfix for kfolds

Fix bugs in closuretest

Added systype files for ATLAS correlation/decorrelation model for some data at 8 TeV c.f. 2112.11266

Simplify docs of convolution module

Remove references to C++ which are now outdated and confusing to new
readers. Simplify example.

Add note on 4.0.5 release

Use `<fitname>.json` by default and deprecate the `.fitinfo` file.

[bot] Add conda environment for tag 4.0.5

Fixed chi2 with thcovmat in report 

Co-authored-by: Roy Stegeman <roystegeman@live.nl>

Remove the nnfit executable and associated documentation

Co-authored-by: Roy Stegeman <roystegeman@live.nl>

The standard convention is for the libraries to be installed to python
prefix relative to the installation prefix, not the system prefix. It
is the a reponsibility of the user or their package manager to
relocate the files or set the correct PYTHONPATH.

This avoids installation errors like:

    CMake Error at libnnpdf/wrapper/cmake_install.cmake:49 (file):
      file cannot create directory:
      /path/to/lib/python3.X/site-packages/NNPDF.
      Maybe need administrative privileges.
    Call Stack (most recent call first):
      libnnpdf/cmake_install.cmake:73 (include)
      cmake_install.cmake:50 (include)

Improve remote keyword functionality

Add note on t0 usage

Check for the type of loader in the comparefits app, so it is explicit
what we are doing.

Co-authored-by: Roy Stegeman <roystegeman@live.nl>

The docs would not do a good job at specifying how to use the t0 chi2.
Add a reference to the main docs so at least it is somewhere visible.