added docs and README.rst
Added LGPL
Added version number.
Added Sphinx documentation
Added link to Sphinx documentation
Added link to Git repository in Sphinx documentation
Transferred introductory paragraph to Sphinx home page
Update documentation
Removed redundant documentation
Added the NeXpy logo
Fixed missing attributes in the Fit class
Minor documentation corrections
Fixed issue when a title is missing in the fitted node
Improved installation documentation
Updated documentation

Added Tree API docstring autodoc
Fixed functions with negative integrals
Made docstrings Sphinx-compatible
Added documentation image
Improved removal of functions in the fit GUI
Improved compatibility of docstrings with Sphinx