special v0.1.2

• Nested sampling: full compatibility added to ultranest sampler for inference of spectral model parameters
• Improved cropped model spectrum before resampling - too conservative crop led to discarding a large fraction of template spectra in template fit
• Improved behaviour for calculation of spectral indices on low spectral resolution spectra
• Updated tutorial with ultranest example and optimized template fitting
• More accurate documentation
• Added JOSS draft + associated workflow for paper compilation
• Version associated to the JOSS paper.