Pyneb

* Remove the old doxygen configuration files and install new schema to build the documentation
* Create updatePyNeb.md that lists the process to make a new realease.
* Accept He2 and He3 in icf.getElemAbundances atom_abun keyword.
* Add HI density keyword to Atom/getIonAbundance method.
* Remove test on numpy version from __init__.py
* important updates to the FeII and FeIII atomic data, coherent with the paper published in Atoms Mendoza+23
* Add a python jupyter Notebook to support the answer to Ueta+Otsuka 2022 paper on Attenuation correction

* emisGrid/plotContours now have a level keyword.
* N3r and N5r added to LINE_LABEL_LIST dictionnary defined in utils/init.py
* o_i_coll_ZT03 added to atomic data
* HeI labels now have a dot after the wavelength (ex: 4471. instead of 4471)
* IPs from utils/physics are now generated also for H and He
recombination lines can now be used in emisGrid
* parseAtom2 returns rec='r' code to identify recombination atoms
* Some minor bugs corrected

* Add the option of using Artificial Neural Network to speed-up getCrossTemDen. This implies the library AI4neb is installed (https://github.com/Morisset/AI4neb) with Tensorflow and Scikit-learn. This will be described in a forthcoming paper, any information can be asked using the Google group.

* File requierements.dev added to root directory (only for developpers).
* A lot of docstrings have been modified to prepare the API documentation
* Directory pyneb/docs reorganized
* A workflow directory is added to automatize the API documentation (all this from MJChimal fork)

* Add eval_diag method in Diagnostic class, to allow the evaluation of a diagnostic
* Correct some bug in using Chianti 7.0
* Optimize the use of Monte Carlo for multiple observations
* Add some labels to LINE_LABEL_LIST
* Add facility in Observation to read fits IFU images, each file corresponding to an emission line
* The default set of atomic data is now PYNENB_21_01
* Add add_sum (adding a new line corresponding to the sum of observed lines) and remove line methods to Observation
* Add an option to include a systematic error to the observations
* Add atomic data from Pequignot et al 1991 for OII recombination lines
* Add "mass" as criterium to print out the emission lines in Observation
* Add Cutout2D options when reading image from fits file, to crop the images

* Updating license files to be coherent with Chianti licenses.
* Adding some units in the docstrings
* Add support for Chianti 10.0 database

* Add example for the use of ANN to getTemDen
* update manuel 9
* Addfacility to use external ANN for getCrossTemDen
* Change the interpolation in Atom to scipy.
* Vectorize some method from the Continuum class
* Add a way to obtained a list of every file used to instantiate Atoms.
* Add KrVI and SeIII from Sterling 2017, and RbIV and BrV
* correct a bug when using copy in place of deepcopy in the managing of the datafile dictionnaries.
* Correct some bung in the Continuum class
* Add ne_iv_atom_MMKV99.dat
* add Fal99 data
* Add o_ii_atom_GFF84.dat
* Create PYNEB_20_01 dictionnary for the new default data files
* Add s_ii_atom_FFTI06.dat, o_ii_atom_HGZJYL14-FFT04.dat, o_ii_atom_HLZSZ18-FFT04.dat, o_ii_atom_HGZJYL14-FFT04.dat, o_ii_atom_CQL07-FFT04.dat, ne_iv_atom_HGZJYL14-FFT04.dat, ne_iv_atom_HLZSZ18-FFT04.dat, s_ii_atom_FFG86.dat
* rename CK73 to CK63
* Correct bug in Continuum: 2-photons was not taking He+ and He++ into account
* Create the deprecated directory to stor files no used anymore, but kept for historical compatibility.

- Adding some atomic data from Tayal et al. 2019 and 2020. No changes in the default data use by PyNeb, user need to explicitly set up these datafiles.
- Add Artificial Neural Network to speedup Atom.getTemDen. Grid.getCrossTemDen already have this facility. Needs the AI4neb library from Morisset github.
- The docs notebooks have be rerun and the corresponding PDF agree with them (was not the case since years due to pdflatex issues).
- DataPlot.plotOmegas does not complain anymore about some axis created multiple times.