Block mentions aren't working in docu-notion

[jamespostsil]

Describe the bug
block-mentions aren't showing up in docu-notion. Notion adds the mention, but docu-notion doesn't display anything.

Note: block mentions are different from page mentions.

** Reproduction Steps **

1. Copy link to a paragraph block (e.g., a heading).
2. Paste-link > Mention block
3. Notion adds the mention, but docu-notion doesn't display anything.

URL of a source Notion page that, when docu-notion accesses or converts it, shows the problem:

At least one of these:

Mention test 1

Mention test 2

Expected behavior
Same/similar as Notion: adds the paragraph text. This is especially helpful for a table of contents for specific headings.

Screenshots

Here's the issue in Notion:

And docu-notion:

Additional context
I demoed this and discussed it a bit here: https://drive.google.com/open?id=1wmaPlH8AYEr3F7orFivUEr4B9gVaZrh8&usp=drive_fs

[andrew-polk]

Pro for block mention:

• If the target text changes, the link text changes. (Of course, this would not be a pro in every scenario... but you wouldn't use it if it wasn't.)

Con for block mention:

• It truncates the link text if it goes beyond 55(?) characters. IMO, this is enough of a con to not use it in the example above.