Parse study helps like the topical guide

[skearnes]

Notable changes:

• Adds support for parsing the topical guide and the index to the triple combination.
• Separates "verses" from "topics" in the underlying data structure; the exported graph also includes a kind node attribute.
• Updates reference parsing, including the ability to handle multiple verses referenced from a single chapter (e.g. "1 Ne. 3:7, 10, 12" now creates three distinct reference targets). This affects the edge counts from my earlier posts.
• Drops tqdm since it was causing pylint to fall into infinite recursion.