Changes to the manuscript

[pawel-czyz]

• [x] Use the NeurIPS template.
• [x] Cite the variational estimators literature (Poole et al., Song and Ermon, McAllester and Stratos)
• [x] Benchmark with tasks created using the BMM models to have a table in the appendix.
• [x] Make Section 4 a Subsection 3.4.
• [ ] Revisit the introduction.
• [x] Revisit the discussion and link to the appendix for more results.
• [x] Answer NeurIPS checklist questions.
• [ ] Update the arXiv version.