Refactor Source to Better Reflect Intention

[wavefunction91]

Closes #61

[susilehtola]

I agree otherwise, but I think that the angular quadratures should be down a further level. The radial rules are in radial/, so the angular rules should be in angular/

[wavefunction91]

@susilehtola I realized that I hadn't pushed a commit where I had already done that (with the exception that angular -> s2 to better reflect the domain of its integration - this code is also being used in e.g. PHF where the integration is more transparantly stated over $S^2$)

[susilehtola]

What’s PHF?

[wavefunction91]

Projected HF, e.g. https://doi.org/10.1021/acs.jctc.7b00832

[susilehtola]

Projected HF, e.g. https://doi.org/10.1021/acs.jctc.7b00832

OK that's what I assumed, I just wasn't familiar with the use of quadrature grids in that approach

[susilehtola]

g2g on my part