Improve spec.bs

[xyaoinum]

Addresses the following issues:

• https://github.com/patcg-individual-drafts/topics/issues/176
• https://github.com/patcg-individual-drafts/topics/issues/177
• https://github.com/patcg-individual-drafts/topics/issues/178
• https://github.com/patcg-individual-drafts/topics/issues/179
• https://github.com/patcg-individual-drafts/topics/issues/180
• https://github.com/patcg-individual-drafts/topics/issues/181
• https://github.com/patcg-individual-drafts/topics/issues/182
• https://github.com/patcg-individual-drafts/topics/issues/183 (already addressed the main issue, but there was one unresolved PR comment in https://github.com/patcg-individual-drafts/topics/pull/186#pullrequestreview-1454530563)

[xyaoinum]

@domenic Domenic: PTAL. Thanks!

[xyaoinum]

@domenic PTAL again. Thanks!