Docs: live examples, quick-start, method comparison page

[cptfinch]

Remaining documentation work (from M2 — site is deployed at cptfinch.github.io/chromadose):

• Live examples (rendered Jupyter notebooks via nbconvert)
• Installation + quick-start as the first page
• Method comparison page (Micke vs Mayer vs Multigaussian vs ANN — accuracy, speed, use cases)