Cannot click/progress the cursor past block elements at the end of the document

[b-kelly]

Umbrella issue to track multiple bugs.

Reported on Meta.SE in the following posts:

• https://meta.stackexchange.com/a/360239/395497
• https://meta.stackexchange.com/a/360057/395497
• https://meta.stackexchange.com/a/360059/395497
• https://meta.stackexchange.com/a/360056/395497

[b-kelly]

Fixed in 2df6573 by always adding a paragraph element when inserting block nodes at the end of the document.