Prepare Physical Review A Letter manuscript

Prepare Physical Review A regular article

Simplify installation instructions

Refine dependencies and README guidance

Update README environment guidance

Refine README wording

Improve README for CPC submission

Add Gaussian mixture plasma profile training notebook and script

Fix parameter name for Magnus check threshold in Solver class

Remove empty .gitkeep file from notebooks directory

Add example notebooks and solver threshold

Update plasma state equation API

Move examples and experiments under test

Switch license to CC BY-NC 3.0

Prepare pre-release snapshot

Add example notebooks and solver threshold

Update plasma state equation API

Move examples and experiments under test