Method documentation

[ci skip]
Memoize MO::Basis#aos and #shells
Memoize MO::Basis::LCAO#overlap, #core_hamiltonian
Rerun profile when (lib|ext)/**/* is modified

[ci skip]
profile RHF_H2O with Libint2 extension
Evaluate only if integrals have not been evaluated
Merge branch 'develop' into feature/libint2
Memoize AO::Gaussian#shell_ao_normalization_factor_ratio