Hi Mary,
Here's the full story.😉

Screenshot #1.- Each Moodle question displays a help button at the top of its Edit/Adding form (1) which displays a minimal help. A click on the More help button (2) takes the user to the full documentation (3). That is perfect.

Screenshot #2.- Unfortunately, the Blocks are missing that Help->More Help button/link (It should be where I have put a big question mark on my screenshot).

Screenshot #3.- This is all the more frustrating for the end-user as there is a documentation page for those blocks!

Screenshot #4.- In my own contributed Export Glossary to Quiz block I have added that link to the documentation page.🥳But this is only possible because that block of mine has an edit form, which is not the case of most blocks.
Finally I am confronted with the "missing link" problem in my contributed Lesson Essay Feedback block, where I cannot find a way to create a link to a documentation page. This is a minor, personal problem, but I thought I would take the opportunity to explain this problem and maybe get solutions...